日別アーカイブ: 2015/06/07

Oracleバージョンによるヒント句の変遷

今週の名言

「世間で頭角をあらわす人物は、自分の望む環境を自ら捜し求める人物であり、もしそれが見つからない時は自分で創り出す人物である。」
ジョージ・バーナード・ショー

今回もトリビアネタ

Oracleエラーを数える回ではとんだ墓穴を掘ってしまいましたが、懲りずに今回はヒント句の種類、しかもOracleのバージョンが進化していく間にどんなヒント句が追加されてきたのかという変遷をたどってみます。

環境は12cR1

今回使用する環境はOracle12cR1です。

SQL> SELECT BANNER FROM V$VERSION;

BANNER
--------------------------------------------------------------------------------
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
PL/SQL Release 12.1.0.2.0 - Production
CORE	12.1.0.2.0	Production
TNS for Linux: Version 12.1.0.2.0 - Production
NLSRTL Version 12.1.0.2.0 - Production

使用するビューはV$SQL_HINT

V$SQL_HINTは11gからあるようですが、ヒント句にどんなのがあるのかを確認できるなかなか面白いビューです。
なぜか12cになってもアンドキュメントなビューなので気になって調べてみました。

ただ、一覧表示させるだけではつまらないので、バージョンごとにまとめて集計してみました。

Oracle8

SQL> SELECT VERSION,CLASS,NAME HINT_NAME,INVERSE,SQL_FEATURE
  2  FROM V$SQL_HINT
  3  ORDER BY
  4   TO_NUMBER(REGEXP_REPLACE(REGEXP_REPLACE(VERSION,'\.','',1,2),'\.','',1,2),99.999)
  5  ,CLASS,NAME;

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
8.0.0      ACCESS                           CLUSTER                                                           QKSFM_CBO
                                            INDEX                            NO_INDEX                         QKSFM_INDEX
                                            QUEUE_CURR                                                        QKSFM_CBO
                                            QUEUE_ROWP                                                        QKSFM_CBO
                                            ROWID                                                             QKSFM_CBO
           ANTIJOIN                         NL_AJ                                                             QKSFM_JOIN_METHOD
           EXPR_CORR_CHECK                  EXPR_CORR_CHECK                                                   QKSFM_CBO
           MERGE                            NO_MERGE                         MERGE                            QKSFM_CVM
           MERGE_CONST_ON                   MERGE_CONST_ON                                                    QKSFM_CBO
           NO_MONITORING                    NO_MONITORING                                                     QKSFM_ALL
           NO_ORDER_ROLLUPS                 NO_ORDER_ROLLUPS                                                  QKSFM_TRANSFORMATION
           NO_STATS_GSETS                   NO_STATS_GSETS                                                    QKSFM_ALL
           ORDERED_PREDICATES               ORDERED_PREDICATES                                                QKSFM_CBO
           SEMIJOIN                         NL_SJ                                                             QKSFM_JOIN_METHOD
********** ******************************** --------------------------------
count                                                                     14

INDEXヒントは8.0.0からあります。
NL_AJ, NL_SJ, NO_MERGE なんかもありますね。
この頃はヒントはまだ14個しかなかったのでしょうか。

Oracle8i

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
8.1.0      ACCESS                           AND_EQUAL                                                         QKSFM_AND_EQUAL
                                            FULL                                                              QKSFM_FULL
                                            HASH                                                              QKSFM_ALL
                                            INDEX_ASC                        NO_INDEX                         QKSFM_INDEX_ASC
                                            INDEX_COMBINE                                                     QKSFM_INDEX_COMBINE
                                            INDEX_DESC                       NO_INDEX                         QKSFM_INDEX_DESC
                                            INDEX_FFS                                                         QKSFM_INDEX_FFS
           ANTIJOIN                         HASH_AJ                                                           QKSFM_JOIN_METHOD
                                            MERGE_AJ                                                          QKSFM_JOIN_METHOD
           APPEND                           APPEND                           NOAPPEND                         QKSFM_CBO
                                            NOAPPEND                         APPEND                           QKSFM_CBO
           BITMAP                           BITMAP                                                            QKSFM_CBO
           CACHE                            CACHE                            NOCACHE                          QKSFM_EXECUTION
                                            NOCACHE                          CACHE                            QKSFM_EXECUTION
           DEREF_NO_REWRITE                 DEREF_NO_REWRITE                                                  QKSFM_ALL
           DRIVING_SITE                     DRIVING_SITE                                                      QKSFM_ALL
           FACT                             FACT                             NO_FACT                          QKSFM_STAR_TRANS
                                            NO_FACT                          FACT                             QKSFM_STAR_TRANS
           JOIN                             USE_HASH                         NO_USE_HASH                      QKSFM_USE_HASH
                                            USE_MERGE                        NO_USE_MERGE                     QKSFM_USE_MERGE
                                            USE_NL                           NO_USE_NL                        QKSFM_USE_NL
           MERGE                            MERGE                            NO_MERGE                         QKSFM_CVM
           MODE                             ALL_ROWS                                                          QKSFM_ALL_ROWS
                                            CHOOSE                                                            QKSFM_CHOOSE
                                            FIRST_ROWS                                                        QKSFM_FIRST_ROWS
                                            RULE                                                              QKSFM_RBO
           NESTED_TABLE_GET_REFS            NESTED_TABLE_GET_REFS                                             QKSFM_ALL
           ORDERED                          ORDERED                                                           QKSFM_CBO
           PARALLEL_INDEX                   NO_PARALLEL_INDEX                PARALLEL_INDEX                   QKSFM_PQ
                                            PARALLEL_INDEX                   NO_PARALLEL_INDEX                QKSFM_PQ
           PIV_GB                           PIV_GB                                                            QKSFM_ALL
                                            TIV_GB                                                            QKSFM_ALL
           PIV_SSF                          PIV_SSF                                                           QKSFM_ALL
                                            TIV_SSF                                                           QKSFM_ALL
           PUSH_PRED                        NO_PUSH_PRED                     PUSH_PRED                        QKSFM_FILTER_PUSH_PRED
                                            PUSH_PRED                        NO_PUSH_PRED                     QKSFM_FILTER_PUSH_PRED
           PUSH_SUBQ                        PUSH_SUBQ                        NO_PUSH_SUBQ                     QKSFM_TRANSFORMATION
           REMOTE_MAPPED                    REMOTE_MAPPED                                                     QKSFM_ALL
           SEMIJOIN                         HASH_SJ                                                           QKSFM_JOIN_METHOD
                                            MERGE_SJ                                                          QKSFM_JOIN_METHOD
           SEMIJOIN_DRIVER                  SEMIJOIN_DRIVER                                                   QKSFM_CBO
           SHARED                           NOPARALLEL                       SHARED                           QKSFM_PARALLEL
                                            SHARED                           NO_PARALLEL                      QKSFM_PARALLEL
           STAR                             STAR                                                              QKSFM_STAR_TRANS
           STAR_TRANSFORMATION              STAR_TRANSFORMATION              NO_STAR_TRANSFORMATION           QKSFM_STAR_TRANS
           SWAP_JOIN_INPUTS                 SWAP_JOIN_INPUTS                 NO_SWAP_JOIN_INPUTS              QKSFM_CBO
           USE_ANTI                         USE_ANTI                                                          QKSFM_CBO
           USE_CONCAT                       NO_EXPAND                        USE_CONCAT                       QKSFM_USE_CONCAT
                                            USE_CONCAT                       NO_EXPAND                        QKSFM_USE_CONCAT
           USE_SEMI                         USE_SEMI                                                          QKSFM_CBO
********** ******************************** --------------------------------
count                                                                     50

Oracle8iから一気に増えます。
FULLやINDEX関連のヒント、HASHヒントなんかもあります。RULEもありますね。

Oracle8i(8.1.5〜)

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
8.1.5      ACCESS                           INDEX_JOIN                                                        QKSFM_INDEX_JOIN
           BUFFER                           BUFFER                           NO_BUFFER                        QKSFM_CBO
                                            NO_BUFFER                        BUFFER                           QKSFM_CBO
           BYPASS_UJVC                      BYPASS_UJVC                                                       QKSFM_CBO
           CACHE                            CACHE_TEMP_TABLE                 NOCACHE                          QKSFM_ALL
           CACHE_CB                         CACHE_CB                         NOCACHE                          QKSFM_CBO
           CUBE_GB                          CUBE_GB                                                           QKSFM_CBO
           DOMAIN_INDEX_SORT                DOMAIN_INDEX_NO_SORT             DOMAIN_INDEX_SORT                QKSFM_CBO
                                            DOMAIN_INDEX_SORT                DOMAIN_INDEX_NO_SORT             QKSFM_CBO
           NESTED_TABLE_SET_SETID           NESTED_TABLE_SET_SETID                                            QKSFM_ALL
           NO_ACCESS                        NO_ACCESS                                                         QKSFM_ALL
           NO_INDEX                         NO_INDEX                         INDEX                            QKSFM_INDEX
           PQ_DISTRIBUTE                    PQ_DISTRIBUTE                                                     QKSFM_PQ_DISTRIBUTE
           RESTORE_AS_INTERVALS             RESTORE_AS_INTERVALS                                              QKSFM_CBO
           REWRITE                          NO_REWRITE                       REWRITE                          QKSFM_TRANSFORMATION
                                            REWRITE                          NO_REWRITE                       QKSFM_TRANSFORMATION
           SAVE_AS_INTERVALS                SAVE_AS_INTERVALS                                                 QKSFM_CBO
           SCN_ASCENDING                    SCN_ASCENDING                                                     QKSFM_ALL
********** ******************************** --------------------------------
count                                                                     18

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
8.1.6      LEADING                          LEADING                                                           QKSFM_JOIN_ORDER
           SYS_PARALLEL_TXN                 SYS_PARALLEL_TXN                                                  QKSFM_CBO
           UNNEST                           NO_UNNEST                        UNNEST                           QKSFM_UNNEST
                                            UNNEST                           NO_UNNEST                        QKSFM_UNNEST
********** ******************************** --------------------------------
count                                                                      4

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
8.1.7      LIKE_EXPAND                      LIKE_EXPAND                                                       QKSFM_TRANSFORMATION
           OR_EXPAND                        OR_EXPAND                                                         QKSFM_OR_EXPAND
********** ******************************** --------------------------------
count                                                                      2

8.1.5以降はだいぶ枯れてきた感があります。LEADINGヒントはRULEベース的にFROM句の後のテーブルを記述した順に結合するヒントですが8.1.6からなんですね。

Oracle9i

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
9.0.0      ACCESS                           INDEX_RRS                                                         QKSFM_CBO
                                            INDEX_SS                         NO_INDEX_SS                      QKSFM_INDEX_SS
                                            INDEX_SS_ASC                     NO_INDEX_SS                      QKSFM_INDEX_SS_ASC
                                            INDEX_SS_DESC                    NO_INDEX_SS                      QKSFM_INDEX_SS_DESC
           ANTIJOIN                         ANTIJOIN                                                          QKSFM_TRANSFORMATION
           BYPASS_RECURSIVE_CHECK           BYPASS_RECURSIVE_CHECK                                            QKSFM_ALL
           CARDINALITY                      CARDINALITY                                                       QKSFM_STATS
           CPU_COSTING                      CPU_COSTING                      NO_CPU_COSTING                   QKSFM_CPU_COSTING
                                            NO_CPU_COSTING                   CPU_COSTING                      QKSFM_CPU_COSTING
           CURSOR_SHARING_EXACT             CURSOR_SHARING_EXACT                                              QKSFM_CBO
           DML_UPDATE                       DML_UPDATE                                                        QKSFM_CBO
           GBY_CONC_ROLLUP                  GBY_CONC_ROLLUP                                                   QKSFM_TRANSFORMATION
           HWM_BROKERED                     HWM_BROKERED                                                      QKSFM_CBO
           INLINE                           INLINE                           MATERIALIZE                      QKSFM_TRANSFORMATION
                                            MATERIALIZE                      INLINE                           QKSFM_TRANSFORMATION
           LOCAL_INDEXES                    LOCAL_INDEXES                                                     QKSFM_CBO
           MV_MERGE                         MV_MERGE                                                          QKSFM_TRANSFORMATION
           NO_PRUNE_GSETS                   NO_PRUNE_GSETS                                                    QKSFM_TRANSFORMATION
           OVERFLOW_NOMOVE                  OVERFLOW_NOMOVE                                                   QKSFM_CBO
           PQ_MAP                           PQ_MAP                           PQ_NOMAP                         QKSFM_PQ_MAP
                                            PQ_NOMAP                         PQ_MAP                           QKSFM_PQ_MAP
           SEMIJOIN                         NO_SEMIJOIN                      SEMIJOIN                         QKSFM_TRANSFORMATION
                                            SEMIJOIN                         NO_SEMIJOIN                      QKSFM_TRANSFORMATION
           SKIP_EXT_OPTIMIZER               SKIP_EXT_OPTIMIZER                                                QKSFM_CBO
           SQLLDR                           SQLLDR                                                            QKSFM_CBO
           USE_TTT_FOR_GSETS                USE_TTT_FOR_GSETS                                                 QKSFM_TRANSFORMATION
********** ******************************** --------------------------------
count                                                                     26

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
9.2.0      DYNAMIC_SAMPLING                 DYNAMIC_SAMPLING                                                  QKSFM_DYNAMIC_SAMPLING
           DYNAMIC_SAMPLING_EST_CDN         DYNAMIC_SAMPLING_EST_CDN                                          QKSFM_DYNAMIC_SAMPLING_EST_CDN
           EXPAND_GSET_TO_UNION             EXPAND_GSET_TO_UNION             NO_EXPAND_GSET_TO_UNION          QKSFM_TRANSFORMATION
                                            NO_EXPAND_GSET_TO_UNION          EXPAND_GSET_TO_UNION             QKSFM_TRANSFORMATION
           FORCE_XML_QUERY_REWRITE          FORCE_XML_QUERY_REWRITE          NO_XML_QUERY_REWRITE             QKSFM_XML_REWRITE
                                            NO_XML_QUERY_REWRITE             FORCE_XML_QUERY_REWRITE          QKSFM_XML_REWRITE
           IGNORE_WHERE_CLAUSE              IGNORE_WHERE_CLAUSE                                               QKSFM_ALL
           NO_QKN_BUFF                      NO_QKN_BUFF                                                       QKSFM_CBO
           PUSH_SUBQ                        NO_PUSH_SUBQ                     PUSH_SUBQ                        QKSFM_TRANSFORMATION
           REF_CASCADE_CURSOR               NO_REF_CASCADE                   REF_CASCADE_CURSOR               QKSFM_CBO
                                            REF_CASCADE_CURSOR               NO_REF_CASCADE                   QKSFM_CBO
           SYS_DL_CURSOR                    SYS_DL_CURSOR                                                     QKSFM_CBO
           SYS_RID_ORDER                    SYS_RID_ORDER                                                     QKSFM_ALL
********** ******************************** --------------------------------
count                                                                     13

Oracle9iR1は当時400種類以上の新機能ができたなんて聞きましたが、ヒント句は8iの時と比べると半分くらいしか追加されていません。
マテリアライズド・ビュー関連のヒントが目立ちますが、ダイナミックサンプリングなんかも9iR2からですね。

Oracle10gR1

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
10.1.0.3   FBTSCAN                          FBTSCAN                                                           QKSFM_CBO
           GATHER_PLAN_STATISTICS           GATHER_PLAN_STATISTICS                                            QKSFM_GATHER_PLAN_STATISTICS
           IGNORE_OPTIM_EMBEDDED_HINTS      IGNORE_OPTIM_EMBEDDED_HINTS                                       QKSFM_ALL
           INCLUDE_VERSION                  INCLUDE_VERSION                                                   QKSFM_ALL
           MODEL_DONTVERIFY_UNIQUENESS      MODEL_DONTVERIFY_UNIQUENESS                                       QKSFM_TRANSFORMATION
           MODEL_MIN_ANALYSIS               MODEL_MIN_ANALYSIS                                                QKSFM_TRANSFORMATION
                                            MODEL_NO_ANALYSIS                                                 QKSFM_ALL
           MODEL_PUSH_REF                   MODEL_PUSH_REF                   NO_MODEL_PUSH_REF                QKSFM_TRANSFORMATION
                                            NO_MODEL_PUSH_REF                MODEL_PUSH_REF                   QKSFM_ALL
           NESTED_TABLE_FAST_INSERT         NESTED_TABLE_FAST_INSERT                                          QKSFM_ALL
           NO_INDEX_FFS                     NO_INDEX_FFS                     INDEX_FFS                        QKSFM_INDEX_FFS
           NO_INDEX_SS                      NO_INDEX_SS                      INDEX_SS                         QKSFM_INDEX_SS
           NO_PARTIAL_COMMIT                NO_PARTIAL_COMMIT                                                 QKSFM_CBO
           NO_QUERY_TRANSFORMATION          NO_QUERY_TRANSFORMATION                                           QKSFM_TRANSFORMATION
           NO_USE_HASH                      NO_USE_HASH                      USE_HASH                         QKSFM_USE_HASH
           NO_USE_MERGE                     NO_USE_MERGE                     USE_MERGE                        QKSFM_USE_MERGE
           NO_USE_NL                        NO_USE_NL                        USE_NL                           QKSFM_USE_NL
           OPAQUE_TRANSFORM                 OPAQUE_TRANSFORM                                                  QKSFM_TRANSFORMATION
           OPAQUE_XCANONICAL                OPAQUE_XCANONICAL                                                 QKSFM_TRANSFORMATION
           OPTIMIZER_FEATURES_ENABLE        OPTIMIZER_FEATURES_ENABLE                                         QKSFM_ALL
           OPT_ESTIMATE                     OPT_ESTIMATE                                                      QKSFM_OPT_ESTIMATE
           QB_NAME                          QB_NAME                                                           QKSFM_ALL
           RESTRICT_ALL_REF_CONS            RESTRICT_ALL_REF_CONS                                             QKSFM_ALL
           REWRITE                          NO_BASETABLE_MULTIMV_REWRITE     REWRITE                          QKSFM_ALL
                                            NO_MULTIMV_REWRITE               REWRITE                          QKSFM_ALL
                                            REWRITE_OR_ERROR                                                  QKSFM_TRANSFORMATION
           SET_TO_JOIN                      NO_SET_TO_JOIN                   SET_TO_JOIN                      QKSFM_SET_TO_JOIN
                                            SET_TO_JOIN                      NO_SET_TO_JOIN                   QKSFM_SET_TO_JOIN
           SHARED                           NO_PARALLEL                      SHARED                           QKSFM_CBO
           SKIP_UNQ_UNUSABLE_IDX            SKIP_UNQ_UNUSABLE_IDX                                             QKSFM_CBO
           STAR_TRANSFORMATION              NO_STAR_TRANSFORMATION           STAR_TRANSFORMATION              QKSFM_STAR_TRANS
           STREAMS                          STREAMS                                                           QKSFM_CBO
           SWAP_JOIN_INPUTS                 NO_SWAP_JOIN_INPUTS              SWAP_JOIN_INPUTS                 QKSFM_CBO
           TABLE_STATS                      COLUMN_STATS                                                      QKSFM_STATS
                                            INDEX_STATS                                                       QKSFM_STATS
                                            TABLE_STATS                                                       QKSFM_STATS
           TRACING                          TRACING                                                           QKSFM_EXECUTION
           USE_NL_WITH_INDEX                USE_NL_WITH_INDEX                NO_USE_NL                        QKSFM_USE_NL_WITH_INDEX
           USE_WEAK_NAME_RESL               USE_WEAK_NAME_RESL                                                QKSFM_ALL
           VECTOR_READ                      VECTOR_READ                                                       QKSFM_CBO
           VECTOR_READ_TRACE                VECTOR_READ_TRACE                                                 QKSFM_CBO
           X_DYN_PRUNE                      X_DYN_PRUNE                                                       QKSFM_CBO
********** ******************************** --------------------------------
count                                                                     42

Oracle10gからはまたグッと増えてきました。
特に統計情報関連のヒントが気になります。

Oracle10gR2

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
10.2.0.1   ACCESS                           BITMAP_TREE                                                       QKSFM_BITMAP_TREE
           DBMS_STATS                       DBMS_STATS                                                        QKSFM_DBMS_STATS
           ELIMINATE_JOIN                   ELIMINATE_JOIN                   NO_ELIMINATE_JOIN                QKSFM_TABLE_ELIM
                                            NO_ELIMINATE_JOIN                ELIMINATE_JOIN                   QKSFM_TABLE_ELIM
           ELIMINATE_OBY                    ELIMINATE_OBY                    NO_ELIMINATE_OBY                 QKSFM_OBYE
                                            NO_ELIMINATE_OBY                 ELIMINATE_OBY                    QKSFM_OBYE
           INLINE_XMLTYPE_NT                INLINE_XMLTYPE_NT                                                 QKSFM_ALL
           MODEL_COMPILE_SUBQUERY           MODEL_COMPILE_SUBQUERY                                            QKSFM_TRANSFORMATION
           MODEL_DYNAMIC_SUBQUERY           MODEL_DYNAMIC_SUBQUERY                                            QKSFM_TRANSFORMATION
           NO_CARTESIAN                     NO_CARTESIAN                                                      QKSFM_ALL
           NO_SQL_TUNE                      NO_SQL_TUNE                                                       QKSFM_ALL
           NO_XML_DML_REWRITE               NO_XML_DML_REWRITE                                                QKSFM_XML_REWRITE
           OLD_PUSH_PRED                    OLD_PUSH_PRED                                                     QKSFM_OLD_PUSH_PRED
           OPT_PARAM                        OPT_PARAM                                                         QKSFM_ALL
           OUTLINE                          OUTLINE                                                           QKSFM_ALL
           OUTLINE_LEAF                     OUTLINE_LEAF                                                      QKSFM_ALL
           PRECOMPUTE_SUBQUERY              PRECOMPUTE_SUBQUERY                                               QKSFM_TRANSFORMATION
           PRESERVE_OID                     PRESERVE_OID                                                      QKSFM_ALL
           PULL_PRED                        NO_PULL_PRED                     PULL_PRED                        QKSFM_PULL_PRED
                                            PULL_PRED                        NO_PULL_PRED                     QKSFM_PULL_PRED
           PX_JOIN_FILTER                   NO_PX_JOIN_FILTER                PX_JOIN_FILTER                   QKSFM_PX_JOIN_FILTER
                                            PX_JOIN_FILTER                   NO_PX_JOIN_FILTER                QKSFM_PX_JOIN_FILTER
           RBO_OUTLINE                      RBO_OUTLINE                                                       QKSFM_RBO
           USE_HASH_AGGREGATION             NO_USE_HASH_AGGREGATION          USE_HASH_AGGREGATION             QKSFM_ALL
                                            USE_HASH_AGGREGATION             NO_USE_HASH_AGGREGATION          QKSFM_ALL
********** ******************************** --------------------------------
count                                                                     25

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
10.2.0.2   CONNECT_BY_COST_BASED            CONNECT_BY_COST_BASED            NO_CONNECT_BY_COST_BASED         QKSFM_TRANSFORMATION
                                            NO_CONNECT_BY_COST_BASED         CONNECT_BY_COST_BASED            QKSFM_TRANSFORMATION
           CONNECT_BY_FILTERING             CONNECT_BY_FILTERING             NO_CONNECT_BY_FILTERING          QKSFM_ALL
                                            NO_CONNECT_BY_FILTERING          CONNECT_BY_FILTERING             QKSFM_ALL
********** ******************************** --------------------------------
count                                                                      4

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
10.2.0.3   ACCESS                           NUM_INDEX_KEYS                                                    QKSFM_CBO
           NATIVE_FULL_OUTER_JOIN           NATIVE_FULL_OUTER_JOIN           NO_NATIVE_FULL_OUTER_JOIN        QKSFM_ALL
                                            NO_NATIVE_FULL_OUTER_JOIN        NATIVE_FULL_OUTER_JOIN           QKSFM_ALL
********** ******************************** --------------------------------
count                                                                      3

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
10.2.0.4   CONNECT_BY_COMBINE_SW            CONNECT_BY_COMBINE_SW            NO_CONNECT_BY_COMBINE_SW         QKSFM_ALL
                                            NO_CONNECT_BY_COMBINE_SW         CONNECT_BY_COMBINE_SW            QKSFM_ALL
********** ******************************** --------------------------------
count                                                                      2

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
10.2.0.5   CONNECT_BY_CB_WHR_ONLY           CONNECT_BY_CB_WHR_ONLY           NO_CONNECT_BY_CB_WHR_ONLY        QKSFM_TRANSFORMATION
                                            NO_CONNECT_BY_CB_WHR_ONLY        CONNECT_BY_CB_WHR_ONLY           QKSFM_TRANSFORMATION
           GBY_PUSHDOWN                     GBY_PUSHDOWN                     NO_GBY_PUSHDOWN                  QKSFM_ALL
                                            NO_GBY_PUSHDOWN                  GBY_PUSHDOWN                     QKSFM_ALL
********** ******************************** --------------------------------
count                                                                      4

10gR2ともなると、普段ほとんど使わないようなヒントばかりになってきますね!
これ以降はコメントのしようがないので、そのまま表示させます。

Oracle11g以降

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
11.1.0.6   ACCESS                           INDEX_RS_ASC                                                      QKSFM_INDEX_RS_ASC
                                            INDEX_RS_DESC                                                     QKSFM_INDEX_RS_DESC
                                            NLJ_BATCHING                     NO_NLJ_BATCHING                  QKSFM_EXECUTION
                                            NLJ_PREFETCH                     NO_NLJ_PREFETCH                  QKSFM_EXECUTION
                                            NO_NLJ_BATCHING                  NLJ_BATCHING                     QKSFM_EXECUTION
                                            NO_NLJ_PREFETCH                  NLJ_PREFETCH                     QKSFM_EXECUTION
           CHECK_ACL_REWRITE                CHECK_ACL_REWRITE                NO_CHECK_ACL_REWRITE             QKSFM_CHECK_ACL_REWRITE
           COST_XML_QUERY_REWRITE           COST_XML_QUERY_REWRITE           NO_COST_XML_QUERY_REWRITE        QKSFM_COST_XML_QUERY_REWRITE
           DB_VERSION                       DB_VERSION                                                        QKSFM_ALL
           DOMAIN_INDEX_FILTER              DOMAIN_INDEX_FILTER              NO_DOMAIN_INDEX_FILTER           QKSFM_CBO
           JOIN                             USE_MERGE_CARTESIAN                                               QKSFM_USE_MERGE_CARTESIAN
           MONITOR                          MONITOR                          NO_MONITOR                       QKSFM_ALL
                                            NO_MONITOR                       MONITOR                          QKSFM_ALL
           NO_CHECK_ACL_REWRITE             NO_CHECK_ACL_REWRITE             CHECK_ACL_REWRITE                QKSFM_CHECK_ACL_REWRITE
           NO_COST_XML_QUERY_REWRITE        NO_COST_XML_QUERY_REWRITE        COST_XML_QUERY_REWRITE           QKSFM_COST_XML_QUERY_REWRITE
           NO_DOMAIN_INDEX_FILTER           NO_DOMAIN_INDEX_FILTER           DOMAIN_INDEX_FILTER              QKSFM_CBO
           NO_LOAD                          NO_LOAD                                                           QKSFM_EXECUTION
           OUTER_JOIN_TO_INNER              NO_OUTER_JOIN_TO_INNER           OUTER_JOIN_TO_INNER              QKSFM_OUTER_JOIN_TO_INNER
                                            OUTER_JOIN_TO_INNER              NO_OUTER_JOIN_TO_INNER           QKSFM_OUTER_JOIN_TO_INNER
           PLACE_GROUP_BY                   NO_PLACE_GROUP_BY                PLACE_GROUP_BY                   QKSFM_PLACE_GROUP_BY
                                            PLACE_GROUP_BY                   NO_PLACE_GROUP_BY                QKSFM_PLACE_GROUP_BY
           RESULT_CACHE                     NO_RESULT_CACHE                  RESULT_CACHE                     QKSFM_EXECUTION
                                            RESULT_CACHE                     NO_RESULT_CACHE                  QKSFM_EXECUTION
           SUBQUERY_PRUNING                 NO_SUBQUERY_PRUNING              SUBQUERY_PRUNING                 QKSFM_CBO
                                            SUBQUERY_PRUNING                 NO_SUBQUERY_PRUNING              QKSFM_CBO
           USE_INVISIBLE_INDEXES            NO_USE_INVISIBLE_INDEXES         USE_INVISIBLE_INDEXES            QKSFM_INDEX
                                            USE_INVISIBLE_INDEXES            NO_USE_INVISIBLE_INDEXES         QKSFM_INDEX
           XMLINDEX_REWRITE                 NO_XMLINDEX_REWRITE              XMLINDEX_REWRITE                 QKSFM_XMLINDEX_REWRITE
                                            NO_XMLINDEX_REWRITE_IN_SELECT    XMLINDEX_REWRITE_IN_SELECT       QKSFM_XMLINDEX_REWRITE
                                            XMLINDEX_REWRITE                 NO_XMLINDEX_REWRITE              QKSFM_XMLINDEX_REWRITE
                                            XMLINDEX_REWRITE_IN_SELECT       NO_XMLINDEX_REWRITE_IN_SELECT    QKSFM_XMLINDEX_REWRITE
           XML_DML_RWT_STMT                 XML_DML_RWT_STMT                                                  QKSFM_XML_REWRITE
********** ******************************** --------------------------------
count                                                                     32

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
11.1.0.7   BIND_AWARE                       BIND_AWARE                       NO_BIND_AWARE                    QKSFM_CURSOR_SHARING
                                            NO_BIND_AWARE                    BIND_AWARE                       QKSFM_CURSOR_SHARING
           CHANGE_DUPKEY_ERROR_INDEX        CHANGE_DUPKEY_ERROR_INDEX                                         QKSFM_DML
           IGNORE_ROW_ON_DUPKEY_INDEX       IGNORE_ROW_ON_DUPKEY_INDEX                                        QKSFM_DML
           RETRY_ON_ROW_CHANGE              RETRY_ON_ROW_CHANGE                                               QKSFM_DML
********** ******************************** --------------------------------
count                                                                      5

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
11.2.0.1   APPEND_VALUES                    APPEND_VALUES                    NOAPPEND                         QKSFM_CBO
           COALESCE_SQ                      COALESCE_SQ                      NO_COALESCE_SQ                   QKSFM_COALESCE_SQ
                                            NO_COALESCE_SQ                   COALESCE_SQ                      QKSFM_COALESCE_SQ
           CONNECT_BY_ELIM_DUPS             CONNECT_BY_ELIM_DUPS             NO_CONNECT_BY_ELIM_DUPS          QKSFM_ALL
                                            NO_CONNECT_BY_ELIM_DUPS          CONNECT_BY_ELIM_DUPS             QKSFM_ALL
           DST_UPGRADE_INSERT_CONV          DST_UPGRADE_INSERT_CONV          NO_DST_UPGRADE_INSERT_CONV       QKSFM_ALL
                                            NO_DST_UPGRADE_INSERT_CONV       DST_UPGRADE_INSERT_CONV          QKSFM_ALL
           EXPAND_TABLE                     EXPAND_TABLE                     NO_EXPAND_TABLE                  QKSFM_TABLE_EXPANSION
                                            NO_EXPAND_TABLE                  EXPAND_TABLE                     QKSFM_TABLE_EXPANSION
           FACTORIZE_JOIN                   FACTORIZE_JOIN                   NO_FACTORIZE_JOIN                QKSFM_JOINFAC
                                            NO_FACTORIZE_JOIN                FACTORIZE_JOIN                   QKSFM_JOINFAC
           NO_SUBSTRB_PAD                   NO_SUBSTRB_PAD                                                    QKSFM_EXECUTION
           PLACE_DISTINCT                   NO_PLACE_DISTINCT                PLACE_DISTINCT                   QKSFM_DIST_PLCMT
                                            PLACE_DISTINCT                   NO_PLACE_DISTINCT                QKSFM_DIST_PLCMT
           STATEMENT_QUEUING                NO_STATEMENT_QUEUING             STATEMENT_QUEUING                QKSFM_PARALLEL
                                            STATEMENT_QUEUING                NO_STATEMENT_QUEUING             QKSFM_PARALLEL
           TRANSFORM_DISTINCT_AGG           NO_TRANSFORM_DISTINCT_AGG        TRANSFORM_DISTINCT_AGG           QKSFM_TRANSFORMATION
                                            TRANSFORM_DISTINCT_AGG           NO_TRANSFORM_DISTINCT_AGG        QKSFM_TRANSFORMATION
           XMLINDEX_SEL_IDX_TBL             XMLINDEX_SEL_IDX_TBL                                              QKSFM_ALL
********** ******************************** --------------------------------
count                                                                     19

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
11.2.0.2   TABLE_LOOKUP_BY_NL               NO_TABLE_LOOKUP_BY_NL            TABLE_LOOKUP_BY_NL               QKSFM_TABLE_LOOKUP_BY_NL
                                            TABLE_LOOKUP_BY_NL               NO_TABLE_LOOKUP_BY_NL            QKSFM_TABLE_LOOKUP_BY_NL
           USE_HASH_GBY_FOR_PUSHDOWN        NO_USE_HASH_GBY_FOR_PUSHDOWN     USE_HASH_GBY_FOR_PUSHDOWN        QKSFM_ALL
                                            USE_HASH_GBY_FOR_PUSHDOWN        NO_USE_HASH_GBY_FOR_PUSHDOWN     QKSFM_ALL
           XDB_FASTPATH_INSERT              NO_XDB_FASTPATH_INSERT           XDB_FASTPATH_INSERT              QKSFM_ALL
                                            XDB_FASTPATH_INSERT              NO_XDB_FASTPATH_INSERT           QKSFM_ALL
********** ******************************** --------------------------------
count                                                                      6

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
11.2.0.3   FULL_OUTER_JOIN_TO_OUTER         FULL_OUTER_JOIN_TO_OUTER         NO_FULL_OUTER_JOIN_TO_OUTER      QKSFM_CBO
                                            NO_FULL_OUTER_JOIN_TO_OUTER      FULL_OUTER_JOIN_TO_OUTER         QKSFM_CBO
           NO_SEMI_TO_INNER                 NO_SEMI_TO_INNER                 SEMI_TO_INNER                    QKSFM_CBO
           OUTER_JOIN_TO_ANTI               NO_OUTER_JOIN_TO_ANTI            OUTER_JOIN_TO_ANTI               QKSFM_CBO
                                            OUTER_JOIN_TO_ANTI               NO_OUTER_JOIN_TO_ANTI            QKSFM_CBO
           SEMI_TO_INNER                    SEMI_TO_INNER                    NO_SEMI_TO_INNER                 QKSFM_CBO
********** ******************************** --------------------------------
count                                                                      6

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
11.2.0.4   ENABLE_PARALLEL_DML              DISABLE_PARALLEL_DML             ENABLE_PARALLEL_DML              QKSFM_DML
                                            ENABLE_PARALLEL_DML              DISABLE_PARALLEL_DML             QKSFM_DML
********** ******************************** --------------------------------
count                                                                      2

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
12.1.0.1   ANTIJOIN                         CUBE_AJ                                                           QKSFM_JOIN_METHOD
           AUTO_REOPTIMIZE                  AUTO_REOPTIMIZE                  NO_AUTO_REOPTIMIZE               QKSFM_AUTO_REOPT
                                            NO_AUTO_REOPTIMIZE               AUTO_REOPTIMIZE                  QKSFM_AUTO_REOPT
           BATCH_TABLE_ACCESS_BY_ROWID      BATCH_TABLE_ACCESS_BY_ROWID      NO_BATCH_TABLE_ACCESS_BY_ROWID   QKSFM_EXECUTION
                                            NO_BATCH_TABLE_ACCESS_BY_ROWID   BATCH_TABLE_ACCESS_BY_ROWID      QKSFM_EXECUTION
           BITMAP_AND                       BITMAP_AND                                                        QKSFM_BITMAP_TREE
           CLUSTERING                       CLUSTERING                       NO_CLUSTERING                    QKSFM_CLUSTERING
                                            NO_CLUSTERING                    CLUSTERING                       QKSFM_CLUSTERING
           CLUSTER_BY_ROWID                 CLUSTER_BY_ROWID                 NO_CLUSTER_BY_ROWID              QKSFM_CBO
                                            NO_CLUSTER_BY_ROWID              CLUSTER_BY_ROWID                 QKSFM_CBO
           DATA_SECURITY_REWRITE_LIMIT      DATA_SECURITY_REWRITE_LIMIT      NO_DATA_SECURITY_REWRITE         QKSFM_DATA_SECURITY_REWRITE
                                            NO_DATA_SECURITY_REWRITE         DATA_SECURITY_REWRITE_LIMIT      QKSFM_DATA_SECURITY_REWRITE
           DECORRELATE                      DECORRELATE                      NO_DECORRELATE                   QKSFM_DECORRELATE
                                            NO_DECORRELATE                   DECORRELATE                      QKSFM_DECORRELATE
           GATHER_OPTIMIZER_STATISTICS      GATHER_OPTIMIZER_STATISTICS      NO_GATHER_OPTIMIZER_STATISTICS   QKSFM_DBMS_STATS
                                            NO_GATHER_OPTIMIZER_STATISTICS   GATHER_OPTIMIZER_STATISTICS      QKSFM_DBMS_STATS
           JOIN                             NO_USE_CUBE                      USE_CUBE                         QKSFM_USE_CUBE
                                            USE_CUBE                         NO_USE_CUBE                      QKSFM_USE_CUBE
           PARTIAL_JOIN                     NO_PARTIAL_JOIN                  PARTIAL_JOIN                     QKSFM_PARTIAL_JOIN
                                            PARTIAL_JOIN                     NO_PARTIAL_JOIN                  QKSFM_PARTIAL_JOIN
           PARTIAL_ROLLUP_PUSHDOWN          NO_PARTIAL_ROLLUP_PUSHDOWN       PARTIAL_ROLLUP_PUSHDOWN          QKSFM_PQ
                                            PARTIAL_ROLLUP_PUSHDOWN          NO_PARTIAL_ROLLUP_PUSHDOWN       QKSFM_PQ
           PQ_CONCURRENT_UNION              NO_PQ_CONCURRENT_UNION           PQ_CONCURRENT_UNION              QKSFM_PQ
                                            PQ_CONCURRENT_UNION              NO_PQ_CONCURRENT_UNION           QKSFM_PQ
           PQ_DISTRIBUTE_WINDOW             PQ_DISTRIBUTE_WINDOW                                              QKSFM_PQ
           PQ_FILTER                        PQ_FILTER                                                         QKSFM_PQ
           PQ_REPLICATE                     NO_PQ_REPLICATE                  PQ_REPLICATE                     QKSFM_PQ_REPLICATE
                                            PQ_REPLICATE                     NO_PQ_REPLICATE                  QKSFM_PQ_REPLICATE
           PQ_SKEW                          NO_PQ_SKEW                       PQ_SKEW                          QKSFM_PQ
                                            PQ_SKEW                          NO_PQ_SKEW                       QKSFM_PQ
           PX_FAULT_TOLERANCE               NO_PX_FAULT_TOLERANCE            PX_FAULT_TOLERANCE               QKSFM_PQ
                                            PX_FAULT_TOLERANCE               NO_PX_FAULT_TOLERANCE            QKSFM_PQ
           SEMIJOIN                         CUBE_SJ                                                           QKSFM_JOIN_METHOD
           USE_HIDDEN_PARTITIONS            USE_HIDDEN_PARTITIONS                                             QKSFM_PARTITION
           WITH_PLSQL                       WITH_PLSQL                                                        QKSFM_ALL
           ZONEMAP                          NO_ZONEMAP                       ZONEMAP                          QKSFM_ZONEMAP
                                            ZONEMAP                          NO_ZONEMAP                       QKSFM_ZONEMAP
********** ******************************** --------------------------------
count                                                                     37

VERSION    CLASS                            HINT_NAME                        INVERSE                          SQL_FEATURE
---------- -------------------------------- -------------------------------- -------------------------------- --------------------------------
12.1.0.2   ADAPTIVE_PLAN                    ADAPTIVE_PLAN                    NO_ADAPTIVE_PLAN                 QKSFM_ADAPTIVE_PLAN
                                            NO_ADAPTIVE_PLAN                 ADAPTIVE_PLAN                    QKSFM_ADAPTIVE_PLAN
           ANSI_REARCH                      ANSI_REARCH                      NO_ANSI_REARCH                   QKSFM_ANSI_REARCH
                                            NO_ANSI_REARCH                   ANSI_REARCH                      QKSFM_ANSI_REARCH
           ELIM_GROUPBY                     ELIM_GROUPBY                     NO_ELIM_GROUPBY                  QKSFM_TRANSFORMATION
                                            NO_ELIM_GROUPBY                  ELIM_GROUPBY                     QKSFM_TRANSFORMATION
           INMEMORY                         INMEMORY                         NO_INMEMORY                      QKSFM_EXECUTION
                                            NO_INMEMORY                      INMEMORY                         QKSFM_EXECUTION
           INMEMORY_PRUNING                 INMEMORY_PRUNING                 NO_INMEMORY_PRUNING              QKSFM_EXECUTION
                                            NO_INMEMORY_PRUNING              INMEMORY_PRUNING                 QKSFM_EXECUTION
           USE_VECTOR_AGGREGATION           NO_USE_VECTOR_AGGREGATION        USE_VECTOR_AGGREGATION           QKSFM_VECTOR_AGG
                                            USE_VECTOR_AGGREGATION           NO_USE_VECTOR_AGGREGATION        QKSFM_VECTOR_AGG
           VECTOR_TRANSFORM                 NO_VECTOR_TRANSFORM              VECTOR_TRANSFORM                 QKSFM_VECTOR_AGG
                                            VECTOR_TRANSFORM                 NO_VECTOR_TRANSFORM              QKSFM_VECTOR_AGG
           VECTOR_TRANSFORM_DIMS            NO_VECTOR_TRANSFORM_DIMS         VECTOR_TRANSFORM_DIMS            QKSFM_VECTOR_AGG
                                            VECTOR_TRANSFORM_DIMS            NO_VECTOR_TRANSFORM_DIMS         QKSFM_VECTOR_AGG
           VECTOR_TRANSFORM_FACT            NO_VECTOR_TRANSFORM_FACT         VECTOR_TRANSFORM_FACT            QKSFM_VECTOR_AGG
                                            VECTOR_TRANSFORM_FACT            NO_VECTOR_TRANSFORM_FACT         QKSFM_VECTOR_AGG
********** ******************************** --------------------------------
count                                                                     18

332行が選択されました。

Oracle12cでは全部で332ものヒント句が存在していることがわかります。

SQL_FEATUREとは

上の一覧で一番右端のカラムは「SQL_FEATURE」となっていますが、これは何でしょうか?
マニュアルに掲載されている「V$SYS_OPTIMIZER_ENV」の記述を参照すると、手がかりが見つかります。

「SQL_FEATURE=関連機能の制御ID」とあるので、オプティマイザというのは多くの機能の集合体であって、初期化パラメータやヒント句は個々の機能(SQL_FEATURE)を制御するものなのだろうということが推察できます。

SQL> SELECT SQL_FEATURE,ID,NAME,ISDEFAULT,VALUE,DEFAULT_VALUE FROM V$SYS_OPTIMIZER_ENV
  2  ORDER BY SQL_FEATURE,ID;

SQL_FEATURE                              ID NAME                                     ISD VALUE           DEFAULT_VALUE
-------------------------------- ---------- ---------------------------------------- --- --------------- -------------
QKSFM_ADAPTIVE_PLAN                     411 optimizer_adaptive_features              YES true            true

QKSFM_ALL                                11 cpu_count                                YES 2               2
                                         12 active_instance_count                    YES 1               1
                                         14 hash_area_size                           YES 131072          131072
                                         15 bitmap_merge_area_size                   YES 1048576         1048576
                                         16 sort_area_size                           YES 65536           65536
                                         17 sort_area_retained_size                  YES 0               0
                                         24 pga_aggregate_target                     YES 286720 KB       286720 KB
                                         35 parallel_query_mode                      YES enabled         enabled
                                         36 parallel_dml_mode                        YES disabled        disabled
                                         37 parallel_ddl_mode                        YES enabled         enabled
                                         38 optimizer_mode                           YES all_rows        all_rows
                                        101 workarea_size_policy                     YES auto            auto
                                        167 optimizer_secure_view_merging            YES true            true
                                        212 result_cache_mode                        YES MANUAL          MANUAL
                                        218 transaction_isolation_level              YES read_commited   read_commited
                                        257 is_recur_flags                           YES 0               0
                                        264 db_file_multiblock_read_count            YES 69              69
                                        275 total_cpu_count                          YES 2               2
                                        286 dst_upgrade_insert_conv                  YES true            true
                                        378 PMO_altidx_rebuild                       YES 0               0
                                        389 total_processor_group_count              YES 1               1

QKSFM_AUTO_REOPT                        353 optimizer_adaptive_reporting_only        YES false           false

QKSFM_CBO                                 2 parallel_execution_enabled               YES true            true
                                          9 optimizer_features_enable                YES 12.1.0.2        12.1.0.2
                                         13 parallel_threads_per_cpu                 YES 2               2
                                         48 cursor_sharing                           YES exact           exact
                                         66 optimizer_index_cost_adj                 YES 100             100
                                         67 optimizer_index_caching                  YES 0               0
                                        105 optimizer_dynamic_sampling               YES 2               2
                                        112 statistics_level                         YES typical         typical
                                        114 skip_unusable_indexes                    YES true            true
                                        228 optimizer_use_pending_statistics         YES false           false
                                        238 optimizer_capture_sql_plan_baselines     YES false           false
                                        239 optimizer_use_sql_plan_baselines         YES true            true
                                        441 optimizer_inmemory_aware                 YES true            true

QKSFM_COMPILATION                       466 inmemory_size                            YES 0               0

QKSFM_EXECUTION                         262 cell_offload_processing                  YES true            true
                                        267 cell_offload_compaction                  YES ADAPTIVE        ADAPTIVE
                                        268 cell_offload_plan_display                YES AUTO            AUTO
                                        453 inmemory_force                           YES default         default
                                        454 inmemory_query                           YES enable          enable

QKSFM_INDEX                             258 optimizer_use_invisible_indexes          YES false           false

QKSFM_PARTITION                         323 deferred_segment_creation                YES true            true

QKSFM_PQ                                245 parallel_degree_policy                   YES manual          manual
                                        246 parallel_degree                          YES 0               0
                                        247 parallel_min_time_threshold              YES 10              10
                                        256 parallel_query_default_dop               YES 0               0
                                        272 parallel_degree_limit                    YES 65535           65535
                                        273 parallel_force_local                     YES false           false
                                        274 parallel_max_degree                      YES 4               4
                                        289 parallel_autodop                         YES 0               0
                                        290 parallel_ddldml                          YES 0               0
                                        317 parallel_execution_message_size          YES 16384           16384
                                        369 parallel_degree_level                    YES 100             100
                                        432 parallel_dblink                          YES 0               0

QKSFM_STAR_TRANS                         50 star_transformation_enabled              YES false           false

QKSFM_TRANSFORMATION                     70 query_rewrite_enabled                    YES true            true
                                         71 query_rewrite_integrity                  YES enforced        enforced


59行が選択されました。

まとめ

アクセスパスを固定化するためにヒント句でチューニングするということはよく行われていると思います。

しかし、12cで332種類(11gR2でも約280個)ものヒントがあることを考えると、ヒント句によるチューニングはオプティマイザのほんの一部を制御しているに過ぎないことを理解すべきです。

しかも、バージョンによってヒント句の数は全然違う、つまりオプティマイザの内部仕様はどんどん変わっているので、以前のバージョンで最適であった実行計画が今のバージョンでも最適である保証はないと考えるのが自然なのではないでしょうか。

今回はここまで。