On Thu, Mar 20, 2025 at 09:46:55PM -0400, Sami Imseih wrote: > * For the same reasons as the query identifiers (see above), > > but, I went ahead and commented it similar to how we document > pgstat_report_query_id and pgstat_get_my_query_id routines. > attached is v2-0001
Looks mostly OK from here.. Except for two things.
@@ -2016,6 +2017,17 @@ exec_bind_message(StringInfo input_message)
*/
cplan = GetCachedPlan(psrc, params, NULL, NULL);
+ foreach(lc, cplan->stmt_list)
+ {
+ PlannedStmt *plan = lfirst_node(PlannedStmt, lc);
+
+ if (plan->planId != UINT64CONST(0))
+ {
+ pgstat_report_plan_id(plan->planId, false);
+ break;
+ }
+ }
In exec_bind_message(), the comment at the top of PortalDefineQuery()
tells to not put any code between this call and the GetCachedPlan()
that could issue an error. pgstat_report_plan_id() is OK, but I'd
rather play it safe and set the ID once the portal is defined, based
on portal->stmts instead. That's the same as your patch, but slightly
safer in the long-term, especially if pgstat_report_plan_id() is
twisted in such a way that it introduces a path where it ERRORs.
planner() is the sole place in the core code where the planner hook
can be called. Shouldn't we have at least a call to
pgstat_report_plan_id() after planning a query? At least that should
be the behavior I'd expect, where a module pushes a planId to a
PlannedStmt, then core publishes it to the backend entry in non-force
mode.
bind and execute message paths are OK as they stand, where we set a
plan ID once their portal is defined from its planned statements.
With some adjustments to some comments and the surroundings of the
code, I get the attached. What do you think?
--
Michael
From a7233c1068ecc29026914fcfd4287dbc62ec65d8 Mon Sep 17 00:00:00 2001 From: "Sami Imseih (AWS)" <sims...@dev-dsk-simseih-1d-3940b79e.us-east-1.amazon.com> Date: Wed, 19 Feb 2025 15:56:21 +0000 Subject: [PATCH v3] Allow plugins to set a 64-bit plan identifier There are extensions that wish to compute a plan identifier to distinguish different plans that a particular query may use. Currently, there is no way for such extensions to make this plan identifier available to the core for reporting and other potentially interesting use cases such as plan management. This patch allows extensions to do this by providing a mechanism to track this identifier in the backend_status as well as in PlannedStmt. The reset of the plan identifier is controlled by core and follows the same code path as the query identifier added in 4f0b0966c8. Discussion: https://www.postgresql.org/message-id/flat/CAA5RZ0vyWd4r35uUBUmhngv8XqeiJUkJDDKkLf5LCoWxv-t_pw%40mail.gmail.com --- src/include/nodes/plannodes.h | 3 ++ src/include/utils/backend_status.h | 5 ++ 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 +++++++++++++++++++++ 6 files changed, 95 insertions(+) diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index f78bffd90cf8..658d76225e47 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 1c9b4fe14d06..430ccd7d78e4 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); diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c index e9337a97d174..39c990ae638d 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 141177e74135..566ce5b3cb40 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 0554a4ae3c7b..4d2edb10658b 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 7681b4ba5a99..e1576e64b6d4 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() - * -- 2.49.0
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