diff --git a/doc/src/sgml/event-trigger.sgml b/doc/src/sgml/event-trigger.sgml
index 6f71a27..0a80993 100644
--- a/doc/src/sgml/event-trigger.sgml
+++ b/doc/src/sgml/event-trigger.sgml
@@ -65,6 +65,16 @@
+ The table_rewrite> event occurs just before a table is going to
+ get rewritten by the commands ALTER TABLE. While other
+ control statements are available to rewrite a table,
+ like CLUSTER and VACUUM,
+ the table_rewrite> event is currently only triggered by
+ the ALTER TABLE command, which might or might not need
+ to rewrite the table.
+
+
+
Event triggers (like other functions) cannot be executed in an aborted
transaction. Thus, if a DDL command fails with an error, any associated
ddl_command_end> triggers will not be executed. Conversely,
@@ -120,6 +130,7 @@
ddl_command_start
ddl_command_end
sql_drop
+ table_rewrite
@@ -128,510 +139,595 @@
X
X
-
+ -
ALTER COLLATION
X
X
-
+ -
ALTER CONVERSION
X
X
-
+ -
ALTER DOMAIN
X
X
-
+ -
ALTER EXTENSION
X
X
-
+ -
ALTER FOREIGN DATA WRAPPER
X
X
-
+ -
ALTER FOREIGN TABLE
X
X
X
+ -
ALTER FUNCTION
X
X
-
+ -
ALTER LANGUAGE
X
X
-
+ -
ALTER OPERATOR
X
X
-
+ -
ALTER OPERATOR CLASS
X
X
-
+ -
ALTER OPERATOR FAMILY
X
X
-
+ -
ALTER POLICY
X
X
-
+ -
ALTER SCHEMA
X
X
-
+ -
ALTER SEQUENCE
X
X
-
+ -
ALTER SERVER
X
X
-
+ -
ALTER TABLE
X
X
X
+ X
ALTER TEXT SEARCH CONFIGURATION
X
X
-
+ -
ALTER TEXT SEARCH DICTIONARY
X
X
-
+ -
ALTER TEXT SEARCH PARSER
X
X
-
+ -
ALTER TEXT SEARCH TEMPLATE
X
X
-
+ -
ALTER TRIGGER
X
X
-
+ -
ALTER TYPE
X
X
-
+ -
ALTER USER MAPPING
X
X
-
+ -
ALTER VIEW
X
X
-
+ -
CREATE AGGREGATE
X
X
-
+ -
CREATE CAST
X
X
-
+ -
CREATE COLLATION
X
X
-
+ -
CREATE CONVERSION
X
X
-
+ -
CREATE DOMAIN
X
X
-
+ -
CREATE EXTENSION
X
X
-
+ -
CREATE FOREIGN DATA WRAPPER
X
X
-
+ -
CREATE FOREIGN TABLE
X
X
-
+ -
CREATE FUNCTION
X
X
-
+ -
CREATE INDEX
X
X
-
+ -
CREATE LANGUAGE
X
X
-
+ -
CREATE OPERATOR
X
X
-
+ -
CREATE OPERATOR CLASS
X
X
-
+ -
CREATE OPERATOR FAMILY
X
X
-
+ -
CREATE POLICY
X
X
-
+ -
CREATE RULE
X
X
-
+ -
CREATE SCHEMA
X
X
-
+ -
CREATE SEQUENCE
X
X
-
+ -
CREATE SERVER
X
X
-
+ -
CREATE TABLE
X
X
-
+ -
CREATE TABLE AS
X
X
-
+ -
CREATE TEXT SEARCH CONFIGURATION
X
X
-
+ -
CREATE TEXT SEARCH DICTIONARY
X
X
-
+ -
CREATE TEXT SEARCH PARSER
X
X
-
+ -
CREATE TEXT SEARCH TEMPLATE
X
X
-
+ -
CREATE TRIGGER
X
X
-
+ -
CREATE TYPE
X
X
-
+ -
CREATE USER MAPPING
X
X
-
+ -
CREATE VIEW
X
X
-
+ -
DROP AGGREGATE
X
X
X
+ -
DROP CAST
X
X
X
+ -
DROP COLLATION
X
X
X
+ -
DROP CONVERSION
X
X
X
+ -
DROP DOMAIN
X
X
X
+ -
DROP EXTENSION
X
X
X
+ -
DROP FOREIGN DATA WRAPPER
X
X
X
+ -
DROP FOREIGN TABLE
X
X
X
+ -
DROP FUNCTION
X
X
X
+ -
DROP INDEX
X
X
X
+ -
DROP LANGUAGE
X
X
X
+ -
DROP OPERATOR
X
X
X
+ -
DROP OPERATOR CLASS
X
X
X
+ -
DROP OPERATOR FAMILY
X
X
X
+ -
DROP OWNED
X
X
X
+ -
DROP POLICY
X
X
X
+ -
DROP RULE
X
X
X
+ -
DROP SCHEMA
X
X
X
+ -
DROP SEQUENCE
X
X
X
+ -
DROP SERVER
X
X
X
+ -
DROP TABLE
X
X
X
+ -
DROP TEXT SEARCH CONFIGURATION
X
X
X
+ -
DROP TEXT SEARCH DICTIONARY
X
X
X
+ -
DROP TEXT SEARCH PARSER
X
X
X
+ -
DROP TEXT SEARCH TEMPLATE
X
X
X
+ -
DROP TRIGGER
X
X
X
+ -
DROP TYPE
X
X
X
+ -
DROP USER MAPPING
X
X
X
+ -
DROP VIEW
X
X
X
+ -
IMPORT FOREIGN SCHEMA
X
X
-
+ -
SELECT INTO
X
X
-
+ -
@@ -843,4 +939,58 @@ COMMIT;
event triggers.)
+
+
+ A Table Rewrite Event Trigger Example
+
+
+ Thanks to the table_rewrite> event, it is possible to implement
+ a table rewriting policy only allowing the rewrite in maintenance windows.
+
+
+
+ Here's an example implementing such a policy.
+
+CREATE OR REPLACE FUNCTION no_rewrite()
+ RETURNS event_trigger
+ LANGUAGE plpgsql AS
+$$
+---
+--- Implement local Table Rewriting policy:
+--- public.foo is not allowed rewriting, ever
+--- other tables are only allowed rewriting between 1am and 6am
+--- unless they have more than 100 blocks
+---
+DECLARE
+ table_oid oid := pg_event_trigger_table_rewrite_oid();
+ current_hour integer := extract('hour' from current_time);
+ pages integer;
+ max_pages integer := 100;
+BEGIN
+ IF pg_event_trigger_table_rewrite_oid() = 'public.foo'::regclass
+ THEN
+ RAISE EXCEPTION 'you''re not allowed to rewrite the table %',
+ table_oid::regclass;
+ END IF;
+
+ SELECT INTO pages relpages FROM pg_class WHERE oid = table_oid;
+ IF pages > max_pages
+ THEN
+ RAISE EXCEPTION 'rewrites only allowed for table with less than % pages',
+ max_pages;
+ END IF;
+
+ IF current_hour NOT BETWEEN 1 AND 6
+ THEN
+ RAISE EXCEPTION 'rewrites only allowed between 1am and 6am';
+ END IF;
+END;
+$$;
+
+CREATE EVENT TRIGGER no_rewrite_allowed
+ ON table_rewrite
+ EXECUTE PROCEDURE no_rewrite();
+
+
+
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7e5bcd9..abe92ad 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -17540,16 +17540,20 @@ FOR EACH ROW EXECUTE PROCEDURE suppress_redundant_updates_trigger();
Event Trigger Functions
+
+ Currently PostgreSQL> provides two built-in event trigger
+ helper function, pg_event_trigger_dropped_objects>
+ and pg_event_trigger_table_rewrite_oid>.
+
+
+
+ Processing objects dropped by a DDL command.
+
pg_event_trigger_dropped_objects
- Currently PostgreSQL> provides one built-in event trigger
- helper function, pg_event_trigger_dropped_objects>.
-
-
-
pg_event_trigger_dropped_objects> returns a list of all objects
dropped by the command in whose sql_drop> event it is called.
If called in any other context,
@@ -17647,6 +17651,68 @@ CREATE EVENT TRIGGER test_event_trigger_for_drops
For more information about event triggers,
see .
+
+
+
+ Handling a Table Rewrite Event
+
+
+ pg_event_trigger_table_rewrite_oid
+
+
+
+ pg_event_trigger_table_rewrite_oid> returns
+ the OID> of the table that is going to be rewritten on-disk by
+ the current DDL command. If called in any other context,
+ pg_event_trigger_table_rewrite_oid> raises an error.
+ pg_event_trigger_table_rewrite_oid> returns the following
+ columns:
+
+
+
+
+
+ Name
+ Type
+ Description
+
+
+
+
+
+ oid
+ Oid
+ OID of the pg_class entry for the table.
+
+
+
+
+
+
+
+ The pg_event_trigger_table_rewrite_oid> function can be used
+ in an event trigger like this:
+
+CREATE FUNCTION test_event_trigger_table_rewrite_oid()
+ RETURNS event_trigger
+ LANGUAGE plpgsql AS
+$$
+BEGIN
+ RAISE NOTICE 'rewriting table %', pg_event_trigger_table_rewrite_oid()::regclass;
+END;
+$$;
+
+CREATE EVENT TRIGGER test_table_rewrite_oid
+ ON table_rewrite
+ EXECUTE PROCEDURE test_event_trigger_table_rewrite_oid();
+
+
+
+
+ For more information about event triggers,
+ see .
+
+
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index 1b8c94b..7b24a74 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -42,11 +42,14 @@
#include "utils/syscache.h"
#include "tcop/utility.h"
-
+/*
+ * Data Structure for sql_drop and table_rewrite Event Trigger support.
+ */
typedef struct EventTriggerQueryState
{
slist_head SQLDropList;
bool in_sql_drop;
+ Oid table_rewrite_oid;
MemoryContext cxt;
struct EventTriggerQueryState *previous;
} EventTriggerQueryState;
@@ -119,11 +122,14 @@ static void AlterEventTriggerOwner_internal(Relation rel,
HeapTuple tup,
Oid newOwnerId);
static event_trigger_command_tag_check_result check_ddl_tag(const char *tag);
+static event_trigger_command_tag_check_result check_table_rewrite_ddl_tag(
+ const char *tag);
static void error_duplicate_filter_variable(const char *defname);
static Datum filter_list_to_array(List *filterlist);
static Oid insert_event_trigger_tuple(char *trigname, char *eventname,
Oid evtOwner, Oid funcoid, List *tags);
static void validate_ddl_tags(const char *filtervar, List *taglist);
+static void validate_table_rewrite_tags(const char *filtervar, List *taglist);
static void EventTriggerInvoke(List *fn_oid_list, EventTriggerData *trigdata);
/*
@@ -154,7 +160,8 @@ CreateEventTrigger(CreateEventTrigStmt *stmt)
/* Validate event name. */
if (strcmp(stmt->eventname, "ddl_command_start") != 0 &&
strcmp(stmt->eventname, "ddl_command_end") != 0 &&
- strcmp(stmt->eventname, "sql_drop") != 0)
+ strcmp(stmt->eventname, "sql_drop") != 0 &&
+ strcmp(stmt->eventname, "table_rewrite") != 0)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("unrecognized event name \"%s\"",
@@ -183,6 +190,9 @@ CreateEventTrigger(CreateEventTrigStmt *stmt)
strcmp(stmt->eventname, "sql_drop") == 0)
&& tags != NULL)
validate_ddl_tags("tag", tags);
+ else if (strcmp(stmt->eventname, "table_rewrite") == 0
+ && tags != NULL)
+ validate_table_rewrite_tags("tag", tags);
/*
* Give user a nice error message if an event trigger of the same name
@@ -257,6 +267,7 @@ check_ddl_tag(const char *tag)
/*
* Otherwise, command should be CREATE, ALTER, or DROP.
+ * Or one of ANALYZE, CLUSTER, VACUUM.
*/
if (pg_strncasecmp(tag, "CREATE ", 7) == 0)
obtypename = tag + 7;
@@ -264,6 +275,10 @@ check_ddl_tag(const char *tag)
obtypename = tag + 6;
else if (pg_strncasecmp(tag, "DROP ", 5) == 0)
obtypename = tag + 5;
+ else if (pg_strncasecmp(tag, "ANALYZE", 7) == 0 ||
+ pg_strncasecmp(tag, "CLUSTER", 7) == 0 ||
+ pg_strncasecmp(tag, "VACUUM", 6) == 0)
+ return EVENT_TRIGGER_COMMAND_TAG_OK;
else
return EVENT_TRIGGER_COMMAND_TAG_NOT_RECOGNIZED;
@@ -281,6 +296,41 @@ check_ddl_tag(const char *tag)
}
/*
+ * Validate DDL command tags.
+ */
+static void
+validate_table_rewrite_tags(const char *filtervar, List *taglist)
+{
+ ListCell *lc;
+
+ foreach(lc, taglist)
+ {
+ const char *tag = strVal(lfirst(lc));
+ event_trigger_command_tag_check_result result;
+
+ result = check_table_rewrite_ddl_tag(tag);
+ if (result == EVENT_TRIGGER_COMMAND_TAG_NOT_SUPPORTED)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ /* translator: %s represents an SQL statement name */
+ errmsg("event triggers are not supported for %s",
+ tag)));
+ }
+}
+
+static event_trigger_command_tag_check_result
+check_table_rewrite_ddl_tag(const char *tag)
+{
+ if (pg_strcasecmp(tag, "ALTER TABLE") == 0 ||
+ pg_strcasecmp(tag, "CLUSTER") == 0 ||
+ pg_strcasecmp(tag, "VACUUM") == 0 ||
+ pg_strcasecmp(tag, "ANALYZE") == 0 )
+ return EVENT_TRIGGER_COMMAND_TAG_OK;
+
+ return EVENT_TRIGGER_COMMAND_TAG_NOT_SUPPORTED;
+}
+
+/*
* Complain about a duplicate filter variable.
*/
static void
@@ -641,8 +691,18 @@ EventTriggerCommonSetup(Node *parsetree,
const char *dbgtag;
dbgtag = CreateCommandTag(parsetree);
- if (check_ddl_tag(dbgtag) != EVENT_TRIGGER_COMMAND_TAG_OK)
- elog(ERROR, "unexpected command tag \"%s\"", dbgtag);
+ if (event == EVT_DDLCommandStart ||
+ event == EVT_DDLCommandEnd ||
+ event == EVT_SQLDrop)
+ {
+ if (check_ddl_tag(dbgtag) != EVENT_TRIGGER_COMMAND_TAG_OK)
+ elog(ERROR, "unexpected command tag \"%s\"", dbgtag);
+ }
+ else if (event == EVT_TableRewrite)
+ {
+ if(check_table_rewrite_ddl_tag(dbgtag) != EVENT_TRIGGER_COMMAND_TAG_OK)
+ elog(ERROR, "unexpected command tag \"%s\"", dbgtag);
+ }
}
#endif
@@ -838,6 +898,77 @@ EventTriggerSQLDrop(Node *parsetree)
list_free(runlist);
}
+
+/*
+ * Fire table_rewrite triggers.
+ */
+void
+EventTriggerTableRewrite(Node *parsetree, Oid tableOid)
+{
+ List *runlist;
+ EventTriggerData trigdata;
+
+ elog(DEBUG1, "EventTriggerTableRewrite(%u)", tableOid);
+
+ /*
+ * Event Triggers are completely disabled in standalone mode. There are
+ * (at least) two reasons for this:
+ *
+ * 1. A sufficiently broken event trigger might not only render the
+ * database unusable, but prevent disabling itself to fix the situation.
+ * In this scenario, restarting in standalone mode provides an escape
+ * hatch.
+ *
+ * 2. BuildEventTriggerCache relies on systable_beginscan_ordered, and
+ * therefore will malfunction if pg_event_trigger's indexes are damaged.
+ * To allow recovery from a damaged index, we need some operating mode
+ * wherein event triggers are disabled. (Or we could implement
+ * heapscan-and-sort logic for that case, but having disaster recovery
+ * scenarios depend on code that's otherwise untested isn't appetizing.)
+ */
+ if (!IsUnderPostmaster)
+ return;
+
+ runlist = EventTriggerCommonSetup(parsetree,
+ EVT_TableRewrite,
+ "table_rewrite",
+ &trigdata);
+ if (runlist == NIL)
+ return;
+
+ /*
+ * Make sure pg_event_trigger_table_rewrite_oid only works when running
+ * these triggers. Use PG_TRY to ensure table_rewrite_oid is reset even
+ * when one trigger fails. (This is perhaps not necessary, as the
+ * currentState variable will be removed shortly by our caller, but it
+ * seems better to play safe.)
+ */
+ currentEventTriggerState->table_rewrite_oid = tableOid;
+
+ /* Run the triggers. */
+ PG_TRY();
+ {
+ EventTriggerInvoke(runlist, &trigdata);
+ }
+ PG_CATCH();
+ {
+ currentEventTriggerState->table_rewrite_oid = InvalidOid;
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+
+ currentEventTriggerState->table_rewrite_oid = InvalidOid;
+
+ /* Cleanup. */
+ list_free(runlist);
+
+ /*
+ * Make sure anything the event triggers did will be visible to the main
+ * command.
+ */
+ CommandCounterIncrement();
+}
+
/*
* Invoke each event trigger in a list of event triggers.
*/
@@ -871,6 +1002,8 @@ EventTriggerInvoke(List *fn_oid_list, EventTriggerData *trigdata)
FunctionCallInfoData fcinfo;
PgStat_FunctionCallUsage fcusage;
+ elog(DEBUG1, "EventTriggerInvoke %u", fnoid);
+
/*
* We want each event trigger to be able to see the results of the
* previous event trigger's action. Caller is responsible for any
@@ -1026,8 +1159,9 @@ EventTriggerBeginCompleteQuery(void)
MemoryContext cxt;
/*
- * Currently, sql_drop events are the only reason to have event trigger
- * state at all; so if there are none, don't install one.
+ * Currently, sql_drop and table_rewrite events are the only reason to
+ * have event trigger state at all; so if there are none, don't install
+ * one.
*/
if (!trackDroppedObjectsNeeded())
return false;
@@ -1041,6 +1175,7 @@ EventTriggerBeginCompleteQuery(void)
state->cxt = cxt;
slist_init(&(state->SQLDropList));
state->in_sql_drop = false;
+ state->table_rewrite_oid = InvalidOid;
state->previous = currentEventTriggerState;
currentEventTriggerState = state;
@@ -1080,8 +1215,9 @@ EventTriggerEndCompleteQuery(void)
bool
trackDroppedObjectsNeeded(void)
{
- /* true if any sql_drop event trigger exists */
- return list_length(EventCacheLookup(EVT_SQLDrop)) > 0;
+ /* true if any sql_drop or table_rewrite event trigger exists */
+ return list_length(EventCacheLookup(EVT_SQLDrop)) > 0 ||
+ list_length(EventCacheLookup(EVT_TableRewrite)) > 0;
}
/*
@@ -1297,3 +1433,25 @@ pg_event_trigger_dropped_objects(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * pg_event_trigger_table_rewrite_oid
+ *
+ * Make the Oid of the table going to be rewritten available to the user
+ * function run by the Event Trigger.
+ */
+Datum
+pg_event_trigger_table_rewrite_oid(PG_FUNCTION_ARGS)
+{
+ /*
+ * Protect this function from being called out of context
+ */
+ if (!currentEventTriggerState ||
+ currentEventTriggerState->table_rewrite_oid == InvalidOid)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("%s can only be called in a table_rewrite event trigger function",
+ "pg_event_trigger_table_rewrite_oid()")));
+
+ PG_RETURN_OID(currentEventTriggerState->table_rewrite_oid);
+}
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ecdff1e..8c08f46 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -46,6 +46,7 @@
#include "commands/cluster.h"
#include "commands/comment.h"
#include "commands/defrem.h"
+#include "commands/event_trigger.h"
#include "commands/policy.h"
#include "commands/sequence.h"
#include "commands/tablecmds.h"
@@ -303,13 +304,15 @@ static void validateForeignKeyConstraint(char *conname,
static void createForeignKeyTriggers(Relation rel, Oid refRelOid,
Constraint *fkconstraint,
Oid constraintOid, Oid indexOid);
-static void ATController(Relation rel, List *cmds, bool recurse, LOCKMODE lockmode);
+static void ATController(AlterTableStmt *parsetree,
+ Relation rel, List *cmds, bool recurse, LOCKMODE lockmode);
static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
bool recurse, bool recursing, LOCKMODE lockmode);
static void ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode);
static void ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
AlterTableCmd *cmd, LOCKMODE lockmode);
-static void ATRewriteTables(List **wqueue, LOCKMODE lockmode);
+static void ATRewriteTables(AlterTableStmt *parsetree,
+ List **wqueue, LOCKMODE lockmode);
static void ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode);
static AlteredTableInfo *ATGetQueueEntry(List **wqueue, Relation rel);
static void ATSimplePermissions(Relation rel, int allowed_targets);
@@ -2723,7 +2726,8 @@ AlterTable(Oid relid, LOCKMODE lockmode, AlterTableStmt *stmt)
CheckTableNotInUse(rel, "ALTER TABLE");
- ATController(rel, stmt->cmds, interpretInhOption(stmt->relation->inhOpt),
+ ATController(stmt,
+ rel, stmt->cmds, interpretInhOption(stmt->relation->inhOpt),
lockmode);
}
@@ -2746,7 +2750,7 @@ AlterTableInternal(Oid relid, List *cmds, bool recurse)
rel = relation_open(relid, lockmode);
- ATController(rel, cmds, recurse, lockmode);
+ ATController(NULL, rel, cmds, recurse, lockmode);
}
/*
@@ -3015,7 +3019,8 @@ AlterTableGetLockLevel(List *cmds)
}
static void
-ATController(Relation rel, List *cmds, bool recurse, LOCKMODE lockmode)
+ATController(AlterTableStmt *parsetree,
+ Relation rel, List *cmds, bool recurse, LOCKMODE lockmode)
{
List *wqueue = NIL;
ListCell *lcmd;
@@ -3035,7 +3040,7 @@ ATController(Relation rel, List *cmds, bool recurse, LOCKMODE lockmode)
ATRewriteCatalogs(&wqueue, lockmode);
/* Phase 3: scan/rewrite tables as needed */
- ATRewriteTables(&wqueue, lockmode);
+ ATRewriteTables(parsetree, &wqueue, lockmode);
}
/*
@@ -3606,7 +3611,7 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
* ATRewriteTables: ALTER TABLE phase 3
*/
static void
-ATRewriteTables(List **wqueue, LOCKMODE lockmode)
+ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode)
{
ListCell *ltab;
@@ -3709,6 +3714,19 @@ ATRewriteTables(List **wqueue, LOCKMODE lockmode)
heap_close(OldHeap, NoLock);
/*
+ * Fire off an Event Trigger now, before actually rewriting the
+ * table.
+ *
+ * We don't support Event Trigger for nested commands anywhere,
+ * here included, and parstree is given NULL when comming from
+ * AlterTableInternal.
+ *
+ * And fire it only once.
+ */
+ if (parsetree)
+ EventTriggerTableRewrite((Node *)parsetree, tab->relid);
+
+ /*
* Create transient table that will receive the modified data.
*
* Ensure it is marked correctly as logged or unlogged. We have
diff --git a/src/backend/utils/cache/evtcache.c b/src/backend/utils/cache/evtcache.c
index ae71bd6..b9d442c 100644
--- a/src/backend/utils/cache/evtcache.c
+++ b/src/backend/utils/cache/evtcache.c
@@ -169,6 +169,8 @@ BuildEventTriggerCache(void)
event = EVT_DDLCommandEnd;
else if (strcmp(evtevent, "sql_drop") == 0)
event = EVT_SQLDrop;
+ else if (strcmp(evtevent, "table_rewrite") == 0)
+ event = EVT_TableRewrite;
else
continue;
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 4736532..b1e0372 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -4990,6 +4990,8 @@ DESCR("peek at binary changes from replication slot");
/* event triggers */
DATA(insert OID = 3566 ( pg_event_trigger_dropped_objects PGNSP PGUID 12 10 100 0 0 f f f f t t s 0 0 2249 "" "{26,26,23,25,25,25,25}" "{o,o,o,o,o,o,o}" "{classid, objid, objsubid, object_type, schema_name, object_name, object_identity}" _null_ pg_event_trigger_dropped_objects _null_ _null_ _null_ ));
DESCR("list objects dropped by the current command");
+DATA(insert OID = 4566 ( pg_event_trigger_table_rewrite_oid PGNSP PGUID 12 10 100 0 0 f f f f t t s 0 0 26 "" "{26}" "{o}" "{oid}" _null_ pg_event_trigger_table_rewrite_oid _null_ _null_ _null_ ));
+DESCR("return Oid of the table getting rewritten");
/* generic transition functions for ordered-set aggregates */
DATA(insert OID = 3970 ( ordered_set_transition PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 2276" _null_ _null_ _null_ _null_ ordered_set_transition _null_ _null_ _null_ ));
diff --git a/src/include/commands/event_trigger.h b/src/include/commands/event_trigger.h
index 0233f4c..5080f4f 100644
--- a/src/include/commands/event_trigger.h
+++ b/src/include/commands/event_trigger.h
@@ -46,6 +46,7 @@ extern bool EventTriggerSupportsObjectClass(ObjectClass objclass);
extern void EventTriggerDDLCommandStart(Node *parsetree);
extern void EventTriggerDDLCommandEnd(Node *parsetree);
extern void EventTriggerSQLDrop(Node *parsetree);
+extern void EventTriggerTableRewrite(Node *parsetree, Oid tableOid);
extern bool EventTriggerBeginCompleteQuery(void);
extern void EventTriggerEndCompleteQuery(void);
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index fb1b4a4..02b581d 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -1189,6 +1189,7 @@ extern Datum unique_key_recheck(PG_FUNCTION_ARGS);
/* commands/event_trigger.c */
extern Datum pg_event_trigger_dropped_objects(PG_FUNCTION_ARGS);
+extern Datum pg_event_trigger_table_rewrite_oid(PG_FUNCTION_ARGS);
/* commands/extension.c */
extern Datum pg_available_extensions(PG_FUNCTION_ARGS);
diff --git a/src/include/utils/evtcache.h b/src/include/utils/evtcache.h
index c4c284f..4bbd80a 100644
--- a/src/include/utils/evtcache.h
+++ b/src/include/utils/evtcache.h
@@ -20,7 +20,8 @@ typedef enum
{
EVT_DDLCommandStart,
EVT_DDLCommandEnd,
- EVT_SQLDrop
+ EVT_SQLDrop,
+ EVT_TableRewrite
} EventTriggerEvent;
typedef struct
diff --git a/src/test/regress/expected/event_trigger.out b/src/test/regress/expected/event_trigger.out
index d4723b2..dbbb05e 100644
--- a/src/test/regress/expected/event_trigger.out
+++ b/src/test/regress/expected/event_trigger.out
@@ -294,3 +294,40 @@ SELECT * FROM dropped_objects WHERE type = 'schema';
DROP ROLE regression_bob;
DROP EVENT TRIGGER regress_event_trigger_drop_objects;
DROP EVENT TRIGGER undroppable;
+-- only allowed from within an event trigger function, should fail
+select pg_event_trigger_table_rewrite_oid();
+ERROR: pg_event_trigger_table_rewrite_oid() can only be called in a table_rewrite event trigger function
+-- test Table Rewrite Event Trigger
+CREATE OR REPLACE FUNCTION test_evtrig_no_rewrite() RETURNS event_trigger
+LANGUAGE plpgsql AS $$
+BEGIN
+ RAISE EXCEPTION 'I''m sorry Sir, No Rewrite Allowed.';
+END;
+$$;
+create event trigger no_rewrite_allowed on table_rewrite
+ execute procedure test_evtrig_no_rewrite();
+create table rewriteme (id serial primary key, foo float);
+insert into rewriteme
+ select x * 1.001 from generate_series(1, 500) as t(x);
+alter table rewriteme alter column foo type numeric;
+ERROR: I'm sorry Sir, No Rewrite Allowed.
+alter table rewriteme add column baz int default 0;
+ERROR: I'm sorry Sir, No Rewrite Allowed.
+-- test with more than one reason to rewrite a single table
+CREATE OR REPLACE FUNCTION test_evtrig_no_rewrite() RETURNS event_trigger
+LANGUAGE plpgsql AS $$
+BEGIN
+ RAISE NOTICE 'Table ''%'' is being rewritten',
+ pg_event_trigger_table_rewrite_oid()::regclass;
+END;
+$$;
+alter table rewriteme
+ add column onemore int default 0,
+ add column another int default -1,
+ alter column foo type numeric(10,4);
+NOTICE: Table 'rewriteme' is being rewritten
+-- shouldn't trigger a table_rewrite event
+alter table rewriteme alter column foo type numeric(12,4);
+drop table rewriteme;
+drop event trigger no_rewrite_allowed;
+drop function test_evtrig_no_rewrite();
diff --git a/src/test/regress/sql/event_trigger.sql b/src/test/regress/sql/event_trigger.sql
index 11d2ce5..5b452b0 100644
--- a/src/test/regress/sql/event_trigger.sql
+++ b/src/test/regress/sql/event_trigger.sql
@@ -206,3 +206,44 @@ DROP ROLE regression_bob;
DROP EVENT TRIGGER regress_event_trigger_drop_objects;
DROP EVENT TRIGGER undroppable;
+
+-- only allowed from within an event trigger function, should fail
+select pg_event_trigger_table_rewrite_oid();
+
+-- test Table Rewrite Event Trigger
+CREATE OR REPLACE FUNCTION test_evtrig_no_rewrite() RETURNS event_trigger
+LANGUAGE plpgsql AS $$
+BEGIN
+ RAISE EXCEPTION 'I''m sorry Sir, No Rewrite Allowed.';
+END;
+$$;
+
+create event trigger no_rewrite_allowed on table_rewrite
+ execute procedure test_evtrig_no_rewrite();
+
+create table rewriteme (id serial primary key, foo float);
+insert into rewriteme
+ select x * 1.001 from generate_series(1, 500) as t(x);
+alter table rewriteme alter column foo type numeric;
+alter table rewriteme add column baz int default 0;
+
+-- test with more than one reason to rewrite a single table
+CREATE OR REPLACE FUNCTION test_evtrig_no_rewrite() RETURNS event_trigger
+LANGUAGE plpgsql AS $$
+BEGIN
+ RAISE NOTICE 'Table ''%'' is being rewritten',
+ pg_event_trigger_table_rewrite_oid()::regclass;
+END;
+$$;
+
+alter table rewriteme
+ add column onemore int default 0,
+ add column another int default -1,
+ alter column foo type numeric(10,4);
+
+-- shouldn't trigger a table_rewrite event
+alter table rewriteme alter column foo type numeric(12,4);
+
+drop table rewriteme;
+drop event trigger no_rewrite_allowed;
+drop function test_evtrig_no_rewrite();