diff options
Diffstat (limited to 'src/include/utils/plancache.h')
| -rw-r--r-- | src/include/utils/plancache.h | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/src/include/utils/plancache.h b/src/include/utils/plancache.h index 199cc323a28..07ec5318db7 100644 --- a/src/include/utils/plancache.h +++ b/src/include/utils/plancache.h @@ -25,7 +25,8 @@ #include "utils/resowner.h" -/* Forward declaration, to avoid including parsenodes.h here */ +/* Forward declarations, to avoid including parsenodes.h here */ +struct Query; struct RawStmt; /* possible values for plan_cache_mode */ @@ -39,18 +40,31 @@ typedef enum /* GUC parameter */ extern PGDLLIMPORT int plan_cache_mode; +/* Optional callback to editorialize on rewritten parse trees */ +typedef void (*PostRewriteHook) (List *querytree_list, void *arg); + #define CACHEDPLANSOURCE_MAGIC 195726186 #define CACHEDPLAN_MAGIC 953717834 #define CACHEDEXPR_MAGIC 838275847 /* * CachedPlanSource (which might better have been called CachedQuery) - * represents a SQL query that we expect to use multiple times. It stores - * the query source text, the raw parse tree, and the analyzed-and-rewritten + * represents a SQL query that we expect to use multiple times. It stores the + * query source text, the source parse tree, and the analyzed-and-rewritten * query tree, as well as adjunct data. Cache invalidation can happen as a * result of DDL affecting objects used by the query. In that case we discard * the analyzed-and-rewritten query tree, and rebuild it when next needed. * + * There are two ways in which the source query can be represented: either + * as a raw parse tree, or as an analyzed-but-not-rewritten parse tree. + * In the latter case we expect that cache invalidation need not affect + * the parse-analysis results, only the rewriting and planning steps. + * Only one of raw_parse_tree and analyzed_parse_tree can be non-NULL. + * (If both are NULL, the CachedPlanSource represents an empty query.) + * Note that query_string is typically just an empty string when the + * source query is an analyzed parse tree; also, param_types, num_params, + * parserSetup, and parserSetupArg will not be used. + * * An actual execution plan, represented by CachedPlan, is derived from the * CachedPlanSource when we need to execute the query. The plan could be * either generic (usable with any set of plan parameters) or custom (for a @@ -78,7 +92,7 @@ extern PGDLLIMPORT int plan_cache_mode; * though it may be useful if the CachedPlan can be discarded early.) * * A CachedPlanSource has two associated memory contexts: one that holds the - * struct itself, the query source text and the raw parse tree, and another + * struct itself, the query source text and the source parse tree, and another * context that holds the rewritten query tree and associated data. This * allows the query tree to be discarded easily when it is invalidated. * @@ -94,12 +108,15 @@ typedef struct CachedPlanSource { int magic; /* should equal CACHEDPLANSOURCE_MAGIC */ struct RawStmt *raw_parse_tree; /* output of raw_parser(), or NULL */ + struct Query *analyzed_parse_tree; /* analyzed parse tree, or NULL */ const char *query_string; /* source text of query */ CommandTag commandTag; /* command tag for query */ Oid *param_types; /* array of parameter type OIDs, or NULL */ int num_params; /* length of param_types array */ ParserSetupHook parserSetup; /* alternative parameter spec method */ void *parserSetupArg; + PostRewriteHook postRewrite; /* see SetPostRewriteHook */ + void *postRewriteArg; int cursor_options; /* cursor options used for planning */ bool fixed_result; /* disallow change in result tupdesc? */ TupleDesc resultDesc; /* result type; NULL = doesn't return tuples */ @@ -196,6 +213,9 @@ extern void ReleaseAllPlanCacheRefsInOwner(ResourceOwner owner); extern CachedPlanSource *CreateCachedPlan(struct RawStmt *raw_parse_tree, const char *query_string, CommandTag commandTag); +extern CachedPlanSource *CreateCachedPlanForQuery(struct Query *analyzed_parse_tree, + const char *query_string, + CommandTag commandTag); extern CachedPlanSource *CreateOneShotCachedPlan(struct RawStmt *raw_parse_tree, const char *query_string, CommandTag commandTag); @@ -208,6 +228,9 @@ extern void CompleteCachedPlan(CachedPlanSource *plansource, void *parserSetupArg, int cursor_options, bool fixed_result); +extern void SetPostRewriteHook(CachedPlanSource *plansource, + PostRewriteHook postRewrite, + void *postRewriteArg); extern void SaveCachedPlan(CachedPlanSource *plansource); extern void DropCachedPlan(CachedPlanSource *plansource); |