From 2a0cd38da5ccf70461c51a489ee7d25fcd3f26be Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 24 Mar 2025 13:23:42 +0900 Subject: [PATCH] Allow plugins to set a 64-bit plan identifier in PlannedStmt This field can be optionally set in a PlannedStmt through the planner hook, giving extensions the possibility to assign an identifier related to a computed plan. The backend is changed to report it in the backend entry of a process running (including the extended query protocol), with semantics and APIs to set or get it similar to what is used for the existing query ID (introduced in the backend via 4f0b0966c8). The plan ID is reset at the same timing as the query ID. Currently, this information is not added to the system view pg_stat_activity; extensions can access it through PgBackendStatus. Some patches have been proposed to provide some features in the planning area, where a plan identifier is used as a key to know the plan involved (for statistics, plan storage and manipulations, etc.), and the point of this commit is to provide an anchor in the backend that extensions can rely on for future work. The reset of the plan identifier is controlled by core and follows the same pattern as the query identifier added in 4f0b0966c8. The contents of this commit are extracted from a larger set proposed originally by Lukas Fittl, that Sami Imseih has proposed as an independent change, with a few tweaks sprinkled by me. Author: Lukas Fittl Author: Sami Imseih Reviewed-by: Bertrand Drouvot Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/CAP53Pkyow59ajFMHGpmb1BK9WHDypaWtUsS_5DoYUEfsa_Hktg@mail.gmail.com Discussion: https://postgr.es/m/CAA5RZ0vyWd4r35uUBUmhngv8XqeiJUkJDDKkLf5LCoWxv-t_pw@mail.gmail.com --- src/backend/executor/execParallel.c | 1 + src/backend/optimizer/plan/planner.c | 4 ++ src/backend/tcop/postgres.c | 24 +++++++++ src/backend/utils/activity/backend_status.c | 58 +++++++++++++++++++++ src/include/nodes/plannodes.h | 3 ++ src/include/utils/backend_status.h | 5 ++ 6 files changed, 95 insertions(+) diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c index e9337a97d17..39c990ae638 100644 --- a/src/backend/executor/execParallel.c +++ b/src/backend/executor/execParallel.c @@ -175,6 +175,7 @@ ExecSerializePlan(Plan *plan, EState *estate) pstmt = makeNode(PlannedStmt); pstmt->commandType = CMD_SELECT; pstmt->queryId = pgstat_get_my_query_id(); + pstmt->planId = pgstat_get_my_plan_id(); pstmt->hasReturning = false; pstmt->hasModifyingCTE = false; pstmt->canSetTag = true; diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 141177e7413..566ce5b3cb4 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -58,6 +58,7 @@ #include "parser/parsetree.h" #include "partitioning/partdesc.h" #include "rewrite/rewriteManip.h" +#include "utils/backend_status.h" #include "utils/lsyscache.h" #include "utils/rel.h" #include "utils/selfuncs.h" @@ -291,6 +292,9 @@ planner(Query *parse, const char *query_string, int cursorOptions, result = (*planner_hook) (parse, query_string, cursorOptions, boundParams); else result = standard_planner(parse, query_string, cursorOptions, boundParams); + + pgstat_report_plan_id(result->planId, false); + return result; } diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index 0554a4ae3c7..4d2edb10658 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -1107,6 +1107,7 @@ exec_simple_query(const char *query_string) size_t cmdtaglen; pgstat_report_query_id(0, true); + pgstat_report_plan_id(0, true); /* * Get the command name for use in status display (it also becomes the @@ -2030,6 +2031,18 @@ exec_bind_message(StringInfo input_message) cplan, psrc); + /* Portal is defined, set the plan ID based on its contents. */ + foreach(lc, portal->stmts) + { + PlannedStmt *plan = lfirst_node(PlannedStmt, lc); + + if (plan->planId != UINT64CONST(0)) + { + pgstat_report_plan_id(plan->planId, false); + break; + } + } + /* Done with the snapshot used for parameter I/O and parsing/planning */ if (snapshot_set) PopActiveSnapshot(); @@ -2170,6 +2183,17 @@ exec_execute_message(const char *portal_name, long max_rows) } } + foreach(lc, portal->stmts) + { + PlannedStmt *stmt = lfirst_node(PlannedStmt, lc); + + if (stmt->planId != UINT64CONST(0)) + { + pgstat_report_plan_id(stmt->planId, false); + break; + } + } + cmdtagname = GetCommandTagNameAndLen(portal->commandTag, &cmdtaglen); set_ps_display_with_len(cmdtagname, cmdtaglen); diff --git a/src/backend/utils/activity/backend_status.c b/src/backend/utils/activity/backend_status.c index 7681b4ba5a9..e1576e64b6d 100644 --- a/src/backend/utils/activity/backend_status.c +++ b/src/backend/utils/activity/backend_status.c @@ -321,6 +321,7 @@ pgstat_bestart_initial(void) lbeentry.st_progress_command = PROGRESS_COMMAND_INVALID; lbeentry.st_progress_command_target = InvalidOid; lbeentry.st_query_id = UINT64CONST(0); + lbeentry.st_plan_id = UINT64CONST(0); /* * we don't zero st_progress_param here to save cycles; nobody should @@ -599,6 +600,7 @@ pgstat_report_activity(BackendState state, const char *cmd_str) /* st_xact_start_timestamp and wait_event_info are also disabled */ beentry->st_xact_start_timestamp = 0; beentry->st_query_id = UINT64CONST(0); + beentry->st_plan_id = UINT64CONST(0); proc->wait_event_info = 0; PGSTAT_END_WRITE_ACTIVITY(beentry); } @@ -659,7 +661,10 @@ pgstat_report_activity(BackendState state, const char *cmd_str) * identifier. */ if (state == STATE_RUNNING) + { beentry->st_query_id = UINT64CONST(0); + beentry->st_plan_id = UINT64CONST(0); + } if (cmd_str != NULL) { @@ -710,6 +715,44 @@ pgstat_report_query_id(uint64 query_id, bool force) PGSTAT_END_WRITE_ACTIVITY(beentry); } +/* -------- + * pgstat_report_plan_id() - + * + * Called to update top-level plan identifier. + * -------- + */ +void +pgstat_report_plan_id(uint64 plan_id, bool force) +{ + volatile PgBackendStatus *beentry = MyBEEntry; + + /* + * if track_activities is disabled, st_plan_id should already have been + * reset + */ + if (!beentry || !pgstat_track_activities) + return; + + /* + * We only report the top-level plan identifiers. The stored plan_id is + * reset when a backend calls pgstat_report_activity(STATE_RUNNING), or + * with an explicit call to this function using the force flag. If the + * saved plan identifier is not zero it means that it's not a top-level + * command, so ignore the one provided unless it's an explicit call to + * reset the identifier. + */ + if (beentry->st_plan_id != 0 && !force) + return; + + /* + * Update my status entry, following the protocol of bumping + * st_changecount before and after. We use a volatile pointer here to + * ensure the compiler doesn't try to get cute. + */ + PGSTAT_BEGIN_WRITE_ACTIVITY(beentry); + beentry->st_plan_id = plan_id; + PGSTAT_END_WRITE_ACTIVITY(beentry); +} /* ---------- * pgstat_report_appname() - @@ -1106,6 +1149,21 @@ pgstat_get_my_query_id(void) return MyBEEntry->st_query_id; } +/* ---------- + * pgstat_get_my_plan_id() - + * + * Return current backend's plan identifier. + */ +uint64 +pgstat_get_my_plan_id(void) +{ + if (!MyBEEntry) + return 0; + + /* No need for a lock, for roughly the same reasons as above. */ + return MyBEEntry->st_plan_id; +} + /* ---------- * pgstat_get_backend_type_by_proc_number() - * diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index f78bffd90cf..658d76225e4 100644 --- a/src/include/nodes/plannodes.h +++ b/src/include/nodes/plannodes.h @@ -55,6 +55,9 @@ typedef struct PlannedStmt /* query identifier (copied from Query) */ uint64 queryId; + /* plan identifier (can be set by plugins) */ + uint64 planId; + /* is it insert|update|delete|merge RETURNING? */ bool hasReturning; diff --git a/src/include/utils/backend_status.h b/src/include/utils/backend_status.h index 1c9b4fe14d0..430ccd7d78e 100644 --- a/src/include/utils/backend_status.h +++ b/src/include/utils/backend_status.h @@ -171,6 +171,9 @@ typedef struct PgBackendStatus /* query identifier, optionally computed using post_parse_analyze_hook */ uint64 st_query_id; + + /* plan identifier, optionally computed using planner_hook */ + uint64 st_plan_id; } PgBackendStatus; @@ -319,6 +322,7 @@ extern void pgstat_clear_backend_activity_snapshot(void); /* Activity reporting functions */ extern void pgstat_report_activity(BackendState state, const char *cmd_str); extern void pgstat_report_query_id(uint64 query_id, bool force); +extern void pgstat_report_plan_id(uint64 plan_id, bool force); extern void pgstat_report_tempfile(size_t filesize); extern void pgstat_report_appname(const char *appname); extern void pgstat_report_xact_timestamp(TimestampTz tstamp); @@ -326,6 +330,7 @@ extern const char *pgstat_get_backend_current_activity(int pid, bool checkUser); extern const char *pgstat_get_crashed_backend_activity(int pid, char *buffer, int buflen); extern uint64 pgstat_get_my_query_id(void); +extern uint64 pgstat_get_my_plan_id(void); extern BackendType pgstat_get_backend_type_by_proc_number(ProcNumber procNumber);