On Sun, Mar 7, 2021 at 12:13 PM Japin Li <japi...@hotmail.com> wrote:
>
> On Sun, 07 Mar 2021 at 14:25, Bharath Rupireddy
> <bharath.rupireddyforpostg...@gmail.com> wrote:
> > On Sun, Mar 7, 2021 at 11:49 AM Japin Li <japi...@hotmail.com> wrote:
> >>
> >> On Fri, 05 Mar 2021 at 19:48, Bharath Rupireddy
> >> <bharath.rupireddyforpostg...@gmail.com> wrote:
> >> > Attaching v5 patch set for further review.
> >> >
> >>
> >> The v5 patch looks good to me, if there is no objection, I'll change the
> >> cf status to "Ready for Committer" in few days.
> >
> > Thanks for the review.
> >
> > As I mentioned upthread, I have 2 open points:
> > 1) In the patch I have added a new mat view info parameter to
> > ExplainOneQuery(), do we also need to add it to
> > ExplainOneQuery_hook_type? IMO, we should not (for now), because this
> > would create a backward compatibility issue.
>
> Sorry, I do not know how PostgreSQL handle the backward compatibility issue.
> Is there a guideline?
I'm not aware of any guidelines as such, but we usually avoid any
changes to existing API, adding/making changes to system catalogs and
so on.
> > 2) Do we document (under respective command pages or somewhere else)
> > that we allow explain/explain analyze for a command?
> >
>
> IMO, we can add a new page to list the commands that can be explain/explain
> analyze,
> since it's clear for users.
We are listing all the supported commands in explain.sgml, so added
the CREATE MATERIALIZED VIEW(it's missing even though it's supported
prior to this patch) and REFRESH MATERIALIZED VIEW there.
Attaching v6 patch set. Please have a look.
With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com
From 26970ffd33e67324609a03f0f61eeb6406216a7f Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddy@enterprisedb.com>
Date: Fri, 5 Mar 2021 15:47:12 +0530
Subject: [PATCH v5 1/2] Rearrange Refresh Mat View Code
Currently, the function ExecRefreshMatView in matview.c is having
many lines of code which is not at all good from readability and
maintainability perspectives. This patch adds few functions and
moves the code from ExecRefreshMatView to them making the code
look better.
---
src/backend/commands/matview.c | 449 ++++++++++++++++++++-------------
1 file changed, 269 insertions(+), 180 deletions(-)
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index c5c25ce11d..18e18fa627 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -64,7 +64,7 @@ static void transientrel_startup(DestReceiver *self, int operation, TupleDesc ty
static bool transientrel_receive(TupleTableSlot *slot, DestReceiver *self);
static void transientrel_shutdown(DestReceiver *self);
static void transientrel_destroy(DestReceiver *self);
-static uint64 refresh_matview_datafill(DestReceiver *dest, Query *query,
+static uint64 refresh_matview_datafill(Oid OIDNewHeap, Query *query,
const char *queryString);
static char *make_temptable_name_n(char *tempname, int n);
static void refresh_by_match_merge(Oid matviewOid, Oid tempOid, Oid relowner,
@@ -73,6 +73,16 @@ static void refresh_by_heap_swap(Oid matviewOid, Oid OIDNewHeap, char relpersist
static bool is_usable_unique_index(Relation indexRel);
static void OpenMatViewIncrementalMaintenance(void);
static void CloseMatViewIncrementalMaintenance(void);
+static Query *get_matview_query(RefreshMatViewStmt *stmt, Relation *rel,
+ Oid *objectId);
+static Query *rewrite_refresh_matview_query(Query *dataQuery);
+static Oid get_new_heap_oid(RefreshMatViewStmt *stmt, Relation matviewRel,
+ Oid matviewOid, char *relpersistence);
+static void match_matview_with_new_data(RefreshMatViewStmt *stmt,
+ Relation matviewRel, Oid matviewOid,
+ Oid OIDNewHeap, Oid relowner,
+ int save_sec_context,
+ char relpersistence, uint64 processed);
/*
* SetMatViewPopulatedState
@@ -140,127 +150,18 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
{
Oid matviewOid;
Relation matviewRel;
- RewriteRule *rule;
- List *actions;
Query *dataQuery;
- Oid tableSpace;
- Oid relowner;
Oid OIDNewHeap;
- DestReceiver *dest;
uint64 processed = 0;
- bool concurrent;
- LOCKMODE lockmode;
+ Oid relowner;
char relpersistence;
Oid save_userid;
int save_sec_context;
int save_nestlevel;
ObjectAddress address;
- /* Determine strength of lock needed. */
- concurrent = stmt->concurrent;
- lockmode = concurrent ? ExclusiveLock : AccessExclusiveLock;
-
- /*
- * Get a lock until end of transaction.
- */
- matviewOid = RangeVarGetRelidExtended(stmt->relation,
- lockmode, 0,
- RangeVarCallbackOwnsTable, NULL);
- matviewRel = table_open(matviewOid, NoLock);
-
- /* Make sure it is a materialized view. */
- if (matviewRel->rd_rel->relkind != RELKIND_MATVIEW)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("\"%s\" is not a materialized view",
- RelationGetRelationName(matviewRel))));
-
- /* Check that CONCURRENTLY is not specified if not populated. */
- if (concurrent && !RelationIsPopulated(matviewRel))
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("CONCURRENTLY cannot be used when the materialized view is not populated")));
-
- /* Check that conflicting options have not been specified. */
- if (concurrent && stmt->skipData)
- ereport(ERROR,
- (errcode(ERRCODE_SYNTAX_ERROR),
- errmsg("CONCURRENTLY and WITH NO DATA options cannot be used together")));
-
- /*
- * Check that everything is correct for a refresh. Problems at this point
- * are internal errors, so elog is sufficient.
- */
- if (matviewRel->rd_rel->relhasrules == false ||
- matviewRel->rd_rules->numLocks < 1)
- elog(ERROR,
- "materialized view \"%s\" is missing rewrite information",
- RelationGetRelationName(matviewRel));
-
- if (matviewRel->rd_rules->numLocks > 1)
- elog(ERROR,
- "materialized view \"%s\" has too many rules",
- RelationGetRelationName(matviewRel));
-
- rule = matviewRel->rd_rules->rules[0];
- if (rule->event != CMD_SELECT || !(rule->isInstead))
- elog(ERROR,
- "the rule for materialized view \"%s\" is not a SELECT INSTEAD OF rule",
- RelationGetRelationName(matviewRel));
-
- actions = rule->actions;
- if (list_length(actions) != 1)
- elog(ERROR,
- "the rule for materialized view \"%s\" is not a single action",
- RelationGetRelationName(matviewRel));
-
- /*
- * Check that there is a unique index with no WHERE clause on one or more
- * columns of the materialized view if CONCURRENTLY is specified.
- */
- if (concurrent)
- {
- List *indexoidlist = RelationGetIndexList(matviewRel);
- ListCell *indexoidscan;
- bool hasUniqueIndex = false;
-
- foreach(indexoidscan, indexoidlist)
- {
- Oid indexoid = lfirst_oid(indexoidscan);
- Relation indexRel;
-
- indexRel = index_open(indexoid, AccessShareLock);
- hasUniqueIndex = is_usable_unique_index(indexRel);
- index_close(indexRel, AccessShareLock);
- if (hasUniqueIndex)
- break;
- }
-
- list_free(indexoidlist);
-
- if (!hasUniqueIndex)
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("cannot refresh materialized view \"%s\" concurrently",
- quote_qualified_identifier(get_namespace_name(RelationGetNamespace(matviewRel)),
- RelationGetRelationName(matviewRel))),
- errhint("Create a unique index with no WHERE clause on one or more columns of the materialized view.")));
- }
-
- /*
- * The stored query was rewritten at the time of the MV definition, but
- * has not been scribbled on by the planner.
- */
- dataQuery = linitial_node(Query, actions);
-
- /*
- * Check for active uses of the relation in the current transaction, such
- * as open scans.
- *
- * NB: We count on this to protect us against problems with refreshing the
- * data using TABLE_INSERT_FROZEN.
- */
- CheckTableNotInUse(matviewRel, "REFRESH MATERIALIZED VIEW");
+ /* Get the data generating query. */
+ dataQuery = get_matview_query(stmt, &matviewRel, &matviewOid);
/*
* Tentatively mark the matview as populated or not (this will roll back
@@ -281,27 +182,8 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
save_sec_context | SECURITY_LOCAL_USERID_CHANGE);
save_nestlevel = NewGUCNestLevel();
- /* Concurrent refresh builds new data in temp tablespace, and does diff. */
- if (concurrent)
- {
- tableSpace = GetDefaultTablespace(RELPERSISTENCE_TEMP, false);
- relpersistence = RELPERSISTENCE_TEMP;
- }
- else
- {
- tableSpace = matviewRel->rd_rel->reltablespace;
- relpersistence = matviewRel->rd_rel->relpersistence;
- }
-
- /*
- * Create the transient table that will receive the regenerated data. Lock
- * it against access by any other process until commit (by which time it
- * will be gone).
- */
- OIDNewHeap = make_new_heap(matviewOid, tableSpace, relpersistence,
- ExclusiveLock);
- LockRelationOid(OIDNewHeap, AccessExclusiveLock);
- dest = CreateTransientRelDestReceiver(OIDNewHeap);
+ OIDNewHeap = get_new_heap_oid(stmt, matviewRel, matviewOid,
+ &relpersistence);
/*
* Now lock down security-restricted operations.
@@ -311,40 +193,16 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
/* Generate the data, if wanted. */
if (!stmt->skipData)
- processed = refresh_matview_datafill(dest, dataQuery, queryString);
-
- /* Make the matview match the newly generated data. */
- if (concurrent)
{
- int old_depth = matview_maintenance_depth;
+ dataQuery = rewrite_refresh_matview_query(dataQuery);
- PG_TRY();
- {
- refresh_by_match_merge(matviewOid, OIDNewHeap, relowner,
- save_sec_context);
- }
- PG_CATCH();
- {
- matview_maintenance_depth = old_depth;
- PG_RE_THROW();
- }
- PG_END_TRY();
- Assert(matview_maintenance_depth == old_depth);
+ processed = refresh_matview_datafill(OIDNewHeap, dataQuery,
+ queryString);
}
- else
- {
- refresh_by_heap_swap(matviewOid, OIDNewHeap, relpersistence);
- /*
- * Inform stats collector about our activity: basically, we truncated
- * the matview and inserted some new data. (The concurrent code path
- * above doesn't need to worry about this because the inserts and
- * deletes it issues get counted by lower-level code.)
- */
- pgstat_count_truncate(matviewRel);
- if (!stmt->skipData)
- pgstat_count_heap_insert(matviewRel, processed);
- }
+ match_matview_with_new_data(stmt, matviewRel, matviewOid, OIDNewHeap,
+ relowner, save_sec_context, relpersistence,
+ processed);
table_close(matviewRel, NoLock);
@@ -373,30 +231,18 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
/*
* refresh_matview_datafill
*
- * Execute the given query, sending result rows to "dest" (which will
- * insert them into the target matview).
+ * Create dest receiver and execute the given query, sending result rows to the
+ * dest receiver which will insert them into the target materialized view.
*
* Returns number of rows inserted.
*/
static uint64
-refresh_matview_datafill(DestReceiver *dest, Query *query,
- const char *queryString)
+refresh_matview_datafill(Oid OIDNewHeap, Query *query, const char *queryString)
{
- List *rewritten;
PlannedStmt *plan;
QueryDesc *queryDesc;
- Query *copied_query;
uint64 processed;
-
- /* Lock and rewrite, using a copy to preserve the original query. */
- copied_query = copyObject(query);
- AcquireRewriteLocks(copied_query, true, false);
- rewritten = QueryRewrite(copied_query);
-
- /* SELECT should never rewrite to more or less than one SELECT query */
- if (list_length(rewritten) != 1)
- elog(ERROR, "unexpected rewrite result for REFRESH MATERIALIZED VIEW");
- query = (Query *) linitial(rewritten);
+ DestReceiver *dest;
/* Check for user-requested abort. */
CHECK_FOR_INTERRUPTS();
@@ -413,6 +259,8 @@ refresh_matview_datafill(DestReceiver *dest, Query *query,
PushCopiedSnapshot(GetActiveSnapshot());
UpdateActiveSnapshotCommandId();
+ dest = CreateTransientRelDestReceiver(OIDNewHeap);
+
/* Create a QueryDesc, redirecting output to our tuple receiver */
queryDesc = CreateQueryDesc(plan, queryString,
GetActiveSnapshot(), InvalidSnapshot,
@@ -933,3 +781,244 @@ CloseMatViewIncrementalMaintenance(void)
matview_maintenance_depth--;
Assert(matview_maintenance_depth >= 0);
}
+
+/*
+ * get_matview_query
+ *
+ * Open the refresh materialized view relation, perform sanity checks and also
+ * get the associated data generating query from it.
+ *
+ * Note that the refresh materialized view relation is opened here, it has to
+ * be closed in the caller.
+ */
+static Query *
+get_matview_query(RefreshMatViewStmt *stmt, Relation *rel, Oid *objectId)
+{
+ Oid matviewOid;
+ Relation matviewRel;
+ RewriteRule *rule;
+ List *actions;
+ Query *dataQuery;
+ LOCKMODE lockmode;
+
+ /* Determine strength of lock needed. */
+ lockmode = stmt->concurrent ? ExclusiveLock : AccessExclusiveLock;
+
+ /* Get a lock until end of transaction. */
+ matviewOid = RangeVarGetRelidExtended(stmt->relation, lockmode, 0,
+ RangeVarCallbackOwnsTable, NULL);
+ matviewRel = table_open(matviewOid, NoLock);
+
+ /* Make sure it is a materialized view. */
+ if (matviewRel->rd_rel->relkind != RELKIND_MATVIEW)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("\"%s\" is not a materialized view",
+ RelationGetRelationName(matviewRel))));
+
+ /* Check that CONCURRENTLY is not specified if not populated. */
+ if (stmt->concurrent && !RelationIsPopulated(matviewRel))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("CONCURRENTLY cannot be used when the materialized view is not populated")));
+
+ /* Check that conflicting options have not been specified. */
+ if (stmt->concurrent && stmt->skipData)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("CONCURRENTLY and WITH NO DATA options cannot be used together")));
+
+ /*
+ * Check that everything is correct for a refresh. Problems at this point
+ * are internal errors, so elog is sufficient.
+ */
+ if (matviewRel->rd_rel->relhasrules == false ||
+ matviewRel->rd_rules->numLocks < 1)
+ elog(ERROR,
+ "materialized view \"%s\" is missing rewrite information",
+ RelationGetRelationName(matviewRel));
+
+ if (matviewRel->rd_rules->numLocks > 1)
+ elog(ERROR,
+ "materialized view \"%s\" has too many rules",
+ RelationGetRelationName(matviewRel));
+
+ rule = matviewRel->rd_rules->rules[0];
+ if (rule->event != CMD_SELECT || !(rule->isInstead))
+ elog(ERROR,
+ "the rule for materialized view \"%s\" is not a SELECT INSTEAD OF rule",
+ RelationGetRelationName(matviewRel));
+
+ actions = rule->actions;
+ if (list_length(actions) != 1)
+ elog(ERROR,
+ "the rule for materialized view \"%s\" is not a single action",
+ RelationGetRelationName(matviewRel));
+
+ /*
+ * Check that there is a unique index with no WHERE clause on one or more
+ * columns of the materialized view if CONCURRENTLY is specified.
+ */
+ if (stmt->concurrent)
+ {
+ List *indexoidlist = RelationGetIndexList(matviewRel);
+ ListCell *indexoidscan;
+ bool hasUniqueIndex = false;
+
+ foreach(indexoidscan, indexoidlist)
+ {
+ Oid indexoid = lfirst_oid(indexoidscan);
+ Relation indexRel;
+
+ indexRel = index_open(indexoid, AccessShareLock);
+ hasUniqueIndex = is_usable_unique_index(indexRel);
+ index_close(indexRel, AccessShareLock);
+ if (hasUniqueIndex)
+ break;
+ }
+
+ list_free(indexoidlist);
+
+ if (!hasUniqueIndex)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot refresh materialized view \"%s\" concurrently",
+ quote_qualified_identifier(get_namespace_name(RelationGetNamespace(matviewRel)),
+ RelationGetRelationName(matviewRel))),
+ errhint("Create a unique index with no WHERE clause on one or more columns of the materialized view.")));
+ }
+
+ /*
+ * The stored query was rewritten at the time of the MV definition, but
+ * has not been scribbled on by the planner.
+ */
+ dataQuery = linitial_node(Query, actions);
+
+ /*
+ * Check for active uses of the relation in the current transaction, such
+ * as open scans.
+ *
+ * NB: We count on this to protect us against problems with refreshing the
+ * data using TABLE_INSERT_FROZEN.
+ */
+ CheckTableNotInUse(matviewRel, "REFRESH MATERIALIZED VIEW");
+
+ *rel = matviewRel;
+ *objectId = matviewOid;
+
+ return dataQuery;
+}
+
+/*
+ * get_new_heap_oid
+ *
+ * Create a new heap and return its oid to which the refresh materialized view
+ * data is inserted into.
+ */
+static Oid
+get_new_heap_oid(RefreshMatViewStmt *stmt, Relation matviewRel, Oid matviewOid,
+ char *relpersistence)
+{
+ Oid OIDNewHeap;
+ Oid tableSpace;
+
+ /* Concurrent refresh builds new data in temp tablespace, and does diff. */
+ if (stmt->concurrent)
+ {
+ tableSpace = GetDefaultTablespace(RELPERSISTENCE_TEMP, false);
+ *relpersistence = RELPERSISTENCE_TEMP;
+ }
+ else
+ {
+ tableSpace = matviewRel->rd_rel->reltablespace;
+ *relpersistence = matviewRel->rd_rel->relpersistence;
+ }
+
+ /*
+ * Create the transient table that will receive the regenerated data. Lock
+ * it against access by any other process until commit (by which time it
+ * will be gone).
+ */
+ OIDNewHeap = make_new_heap(matviewOid, tableSpace, *relpersistence,
+ ExclusiveLock);
+ LockRelationOid(OIDNewHeap, AccessExclusiveLock);
+
+ return OIDNewHeap;
+}
+
+/*
+ * match_matview_with_new_data
+ *
+ * Arrange the materialized view newly generated data to match the existing
+ * data i.e merge in case of CONCURRENTLY otherwise perform heap swap and
+ * truncate the materialized view.
+ */
+static void
+match_matview_with_new_data(RefreshMatViewStmt *stmt, Relation matviewRel,
+ Oid matviewOid, Oid OIDNewHeap, Oid relowner,
+ int save_sec_context, char relpersistence,
+ uint64 processed)
+{
+ /* Make the materialized view match the newly generated data. */
+ if (stmt->concurrent)
+ {
+ int old_depth = matview_maintenance_depth;
+
+ PG_TRY();
+ {
+ refresh_by_match_merge(matviewOid, OIDNewHeap, relowner,
+ save_sec_context);
+ }
+ PG_CATCH();
+ {
+ matview_maintenance_depth = old_depth;
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+ Assert(matview_maintenance_depth == old_depth);
+ }
+ else
+ {
+ refresh_by_heap_swap(matviewOid, OIDNewHeap, relpersistence);
+
+ /*
+ * Inform stats collector about our activity: basically, we truncated
+ * the materialized view and inserted some new data. (The concurrent
+ * code path above doesn't need to worry about this because the
+ * inserts and deletes it issues get counted by lower-level code.)
+ */
+ pgstat_count_truncate(matviewRel);
+ if (!stmt->skipData)
+ pgstat_count_heap_insert(matviewRel, processed);
+ }
+}
+
+/*
+ * rewrite_refresh_matview_query
+ *
+ * Rewrite the refresh materialized view data generating query.
+ *
+ * Work on the copied query to preserve the original query. Because the
+ * rewriter and planner tend to scribble on the input, we make a preliminary
+ * copy of the source querytree. This prevents problems in the case that
+ * REFRESH MATERIALIZED VIEW is in a portal or plpgsql function and is executed
+ * repeatedly. (See also the same hack in EXPLAIN and PREPARE.)
+ */
+static Query *
+rewrite_refresh_matview_query(Query *dataQuery)
+{
+ List *rewritten;
+ Query *copied_query;
+
+ /* Lock and rewrite, using a copy to preserve the original query. */
+ copied_query = copyObject(dataQuery);
+ AcquireRewriteLocks(copied_query, true, false);
+ rewritten = QueryRewrite(copied_query);
+
+ /* SELECT should never rewrite to more or less than one SELECT query */
+ if (list_length(rewritten) != 1)
+ elog(ERROR, "unexpected rewrite result for REFRESH MATERIALIZED VIEW");
+ dataQuery = (Query *) linitial(rewritten);
+
+ return dataQuery;
+}
--
2.25.1
From 08906356cbbd1fe1231d633847552290e9155ec5 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddy@enterprisedb.com>
Date: Sun, 7 Mar 2021 14:57:24 +0530
Subject: [PATCH v6] EXPLAIN/EXPLAIN ANALYZE REFRESH MATERIALIZED VIEW
Currently, explain/explain analyze refresh materialized view(RMV)
is not allowed. We do plan the materialized view query before every
refresh. I propose to show the explain/explain analyze of the
select part of the materialized view. It will be useful for the
user to know what exactly is being planned and executed as part of
RMV. Please note that we already have explain/explain analyze
CTAS/Create Mat View(CMV), where we show the explain/explain analyze
of the select part. This proposal will do the same thing.
The behaviour can be like this:
EXPLAIN REFRESH MATERIALIZED VIEW mv1; --> will not refresh the mat
view, but shows the select part's plan of mat view.
EXPLAIN ANALYZE REFRESH MATERIALIZED VIEW mv1; --> will refresh the
mat view and shows the select part's plan of mat view.
---
doc/src/sgml/ref/explain.sgml | 2 +
src/backend/commands/explain.c | 50 +++++++++++-----
src/backend/commands/matview.c | 36 +++++++++---
src/backend/commands/prepare.c | 3 +-
src/backend/tcop/utility.c | 3 +-
src/include/commands/explain.h | 30 +++++++++-
src/include/commands/matview.h | 8 ++-
src/test/regress/expected/matview.out | 83 +++++++++++++++++++++++++++
src/test/regress/sql/matview.sql | 27 +++++++++
9 files changed, 217 insertions(+), 25 deletions(-)
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
index c4512332a0..a301b6b53f 100644
--- a/doc/src/sgml/ref/explain.sgml
+++ b/doc/src/sgml/ref/explain.sgml
@@ -95,6 +95,8 @@ EXPLAIN [ ANALYZE ] [ VERBOSE ] <replaceable class="parameter">statement</replac
<command>EXPLAIN ANALYZE</command> on an
<command>INSERT</command>, <command>UPDATE</command>,
<command>DELETE</command>, <command>CREATE TABLE AS</command>,
+ <command>CREATE MATERIALIZED VIEW</command>,
+ <command>REFRESH MATERIALIZED VIEW</command>,
or <command>EXECUTE</command> statement
without letting the command affect your data, use this approach:
<programlisting>
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index afc45429ba..ac15931a41 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -17,6 +17,7 @@
#include "catalog/pg_type.h"
#include "commands/createas.h"
#include "commands/defrem.h"
+#include "commands/matview.h"
#include "commands/prepare.h"
#include "executor/nodeHash.h"
#include "foreign/fdwapi.h"
@@ -53,10 +54,6 @@ explain_get_index_name_hook_type explain_get_index_name_hook = NULL;
#define X_CLOSE_IMMEDIATE 2
#define X_NOWHITESPACE 4
-static void ExplainOneQuery(Query *query, int cursorOptions,
- IntoClause *into, ExplainState *es,
- const char *queryString, ParamListInfo params,
- QueryEnvironment *queryEnv);
static void ExplainPrintJIT(ExplainState *es, int jit_flags,
JitInstrumentation *ji);
static void report_triggers(ResultRelInfo *rInfo, bool show_relname,
@@ -274,7 +271,8 @@ ExplainQuery(ParseState *pstate, ExplainStmt *stmt,
{
ExplainOneQuery(lfirst_node(Query, l),
CURSOR_OPT_PARALLEL_OK, NULL, es,
- pstate->p_sourcetext, params, pstate->p_queryEnv);
+ pstate->p_sourcetext, params, pstate->p_queryEnv,
+ NULL);
/* Separate plans with an appropriate separator */
if (lnext(rewritten, l) != NULL)
@@ -357,11 +355,11 @@ ExplainResultDesc(ExplainStmt *stmt)
*
* "into" is NULL unless we are explaining the contents of a CreateTableAsStmt.
*/
-static void
+void
ExplainOneQuery(Query *query, int cursorOptions,
IntoClause *into, ExplainState *es,
const char *queryString, ParamListInfo params,
- QueryEnvironment *queryEnv)
+ QueryEnvironment *queryEnv, RefreshMatViewInfo *matviewInfo)
{
/* planner will not cope with utility statements */
if (query->commandType == CMD_UTILITY)
@@ -402,7 +400,8 @@ ExplainOneQuery(Query *query, int cursorOptions,
/* run it (if needed) and produce output */
ExplainOnePlan(plan, into, es, queryString, params, queryEnv,
- &planduration, (es->buffers ? &bufusage : NULL));
+ &planduration, (es->buffers ? &bufusage : NULL),
+ matviewInfo);
}
}
@@ -455,7 +454,7 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
Assert(list_length(rewritten) == 1);
ExplainOneQuery(linitial_node(Query, rewritten),
CURSOR_OPT_PARALLEL_OK, ctas->into, es,
- queryString, params, queryEnv);
+ queryString, params, queryEnv, NULL);
}
else if (IsA(utilityStmt, DeclareCursorStmt))
{
@@ -474,7 +473,8 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
Assert(list_length(rewritten) == 1);
ExplainOneQuery(linitial_node(Query, rewritten),
dcs->options, NULL, es,
- queryString, params, queryEnv);
+ queryString, params, queryEnv,
+ NULL);
}
else if (IsA(utilityStmt, ExecuteStmt))
ExplainExecuteQuery((ExecuteStmt *) utilityStmt, into, es,
@@ -486,6 +486,16 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
else
ExplainDummyGroup("Notify", NULL, es);
}
+ else if(IsA(utilityStmt, RefreshMatViewStmt))
+ {
+ RefreshMatViewExplainInfo explainInfo;
+
+ explainInfo.es = es;
+ explainInfo.queryEnv = queryEnv;
+
+ ExecRefreshMatView((RefreshMatViewStmt *) utilityStmt,
+ queryString, params, NULL, &explainInfo);
+ }
else
{
if (es->format == EXPLAIN_FORMAT_TEXT)
@@ -512,7 +522,7 @@ void
ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv, const instr_time *planduration,
- const BufferUsage *bufusage)
+ const BufferUsage *bufusage, RefreshMatViewInfo *matviewInfo)
{
DestReceiver *dest;
QueryDesc *queryDesc;
@@ -553,6 +563,8 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
*/
if (into)
dest = CreateIntoRelDestReceiver(into);
+ else if (matviewInfo && OidIsValid(matviewInfo->OIDNewHeap))
+ dest = CreateTransientRelDestReceiver(matviewInfo->OIDNewHeap);
else
dest = None_Receiver;
@@ -577,8 +589,12 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
{
ScanDirection dir;
- /* EXPLAIN ANALYZE CREATE TABLE AS WITH NO DATA is weird */
- if (into && into->skipData)
+ /*
+ * EXPLAIN ANALYZE CREATE TABLE AS or REFRESH MATERIALIZED VIEW
+ * WITH NO DATA is weird.
+ */
+ if ((into && into->skipData) ||
+ (matviewInfo && matviewInfo->skipData))
dir = NoMovementScanDirection;
else
dir = ForwardScanDirection;
@@ -586,6 +602,14 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
/* run the plan */
ExecutorRun(queryDesc, dir, 0L, true);
+ /*
+ * Collect the number of rows inserted in case of REFRESH MATERIALIZED
+ * VIEW which will be used while merging the newly generated data with
+ * the existing materialized view data in ExecRefreshMatView.
+ */
+ if (matviewInfo)
+ matviewInfo->processed = queryDesc->estate->es_processed;
+
/* run cleanup too */
ExecutorFinish(queryDesc);
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index 18e18fa627..5c44d6b451 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -146,7 +146,8 @@ SetMatViewPopulatedState(Relation relation, bool newstate)
*/
ObjectAddress
ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
- ParamListInfo params, QueryCompletion *qc)
+ ParamListInfo params, QueryCompletion *qc,
+ RefreshMatViewExplainInfo *explainInfo)
{
Oid matviewOid;
Relation matviewRel;
@@ -182,8 +183,11 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
save_sec_context | SECURITY_LOCAL_USERID_CHANGE);
save_nestlevel = NewGUCNestLevel();
- OIDNewHeap = get_new_heap_oid(stmt, matviewRel, matviewOid,
- &relpersistence);
+ if (explainInfo && !explainInfo->es->analyze)
+ OIDNewHeap = InvalidOid;
+ else
+ OIDNewHeap = get_new_heap_oid(stmt, matviewRel, matviewOid,
+ &relpersistence);
/*
* Now lock down security-restricted operations.
@@ -192,17 +196,35 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
save_sec_context | SECURITY_RESTRICTED_OPERATION);
/* Generate the data, if wanted. */
- if (!stmt->skipData)
+ if (!stmt->skipData && !explainInfo)
{
dataQuery = rewrite_refresh_matview_query(dataQuery);
processed = refresh_matview_datafill(OIDNewHeap, dataQuery,
queryString);
}
+ else if (explainInfo)
+ {
+ RefreshMatViewInfo matViewInfo;
+
+ matViewInfo.OIDNewHeap = OIDNewHeap;
+ matViewInfo.skipData = stmt->skipData;
+ matViewInfo.processed = 0;
+
+ dataQuery = rewrite_refresh_matview_query(dataQuery);
+
+ ExplainOneQuery(dataQuery,
+ CURSOR_OPT_PARALLEL_OK, NULL, explainInfo->es,
+ queryString, params, explainInfo->queryEnv,
+ &matViewInfo);
+
+ processed = matViewInfo.processed;
+ }
- match_matview_with_new_data(stmt, matviewRel, matviewOid, OIDNewHeap,
- relowner, save_sec_context, relpersistence,
- processed);
+ if (OidIsValid(OIDNewHeap))
+ match_matview_with_new_data(stmt, matviewRel, matviewOid, OIDNewHeap,
+ relowner, save_sec_context, relpersistence,
+ processed);
table_close(matviewRel, NoLock);
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index f767751c71..56c7432879 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -673,7 +673,8 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
if (pstmt->commandType != CMD_UTILITY)
ExplainOnePlan(pstmt, into, es, query_string, paramLI, queryEnv,
- &planduration, (es->buffers ? &bufusage : NULL));
+ &planduration, (es->buffers ? &bufusage : NULL),
+ NULL);
else
ExplainOneUtility(pstmt->utilityStmt, into, es, query_string,
paramLI, queryEnv);
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 05bb698cf4..20087addb4 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -1621,7 +1621,8 @@ ProcessUtilitySlow(ParseState *pstate,
PG_TRY();
{
address = ExecRefreshMatView((RefreshMatViewStmt *) parsetree,
- queryString, params, qc);
+ queryString, params, qc,
+ NULL);
}
PG_FINALLY();
{
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index e94d9e49cf..7f27d92df1 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -61,6 +61,27 @@ typedef struct ExplainState
ExplainWorkersState *workers_state; /* needed if parallel plan */
} ExplainState;
+/*
+ * Refresh Materialized View information passed across functions for EXPLAIN
+ * execution.
+ */
+typedef struct RefreshMatViewInfo
+{
+ /* Oid of the new heap created. */
+ Oid OIDNewHeap;
+ /* Is WITH NO DATA clause specified? */
+ bool skipData;
+ /* Number of rows inserted. */
+ uint64 processed;
+} RefreshMatViewInfo;
+
+/* EXPLAIN information shared to ExecRefreshMatView(). */
+typedef struct RefreshMatViewExplainInfo
+{
+ ExplainState *es;
+ QueryEnvironment *queryEnv;
+} RefreshMatViewExplainInfo;
+
/* Hook for plugins to get control in ExplainOneQuery() */
typedef void (*ExplainOneQuery_hook_type) (Query *query,
int cursorOptions,
@@ -91,7 +112,14 @@ extern void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into,
ExplainState *es, const char *queryString,
ParamListInfo params, QueryEnvironment *queryEnv,
const instr_time *planduration,
- const BufferUsage *bufusage);
+ const BufferUsage *bufusage,
+ RefreshMatViewInfo *matviewInfo);
+
+extern void ExplainOneQuery(Query *query, int cursorOptions,
+ IntoClause *into, ExplainState *es,
+ const char *queryString, ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ RefreshMatViewInfo *matviewInfo);
extern void ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc);
extern void ExplainPrintTriggers(ExplainState *es, QueryDesc *queryDesc);
diff --git a/src/include/commands/matview.h b/src/include/commands/matview.h
index 214b1c1df6..1d60180ebc 100644
--- a/src/include/commands/matview.h
+++ b/src/include/commands/matview.h
@@ -15,6 +15,7 @@
#define MATVIEW_H
#include "catalog/objectaddress.h"
+#include "commands/explain.h"
#include "nodes/params.h"
#include "nodes/parsenodes.h"
#include "tcop/dest.h"
@@ -23,8 +24,11 @@
extern void SetMatViewPopulatedState(Relation relation, bool newstate);
-extern ObjectAddress ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
- ParamListInfo params, QueryCompletion *qc);
+extern ObjectAddress ExecRefreshMatView(RefreshMatViewStmt *stmt,
+ const char *queryString,
+ ParamListInfo params,
+ QueryCompletion *qc,
+ RefreshMatViewExplainInfo *explainInfo);
extern DestReceiver *CreateTransientRelDestReceiver(Oid oid);
diff --git a/src/test/regress/expected/matview.out b/src/test/regress/expected/matview.out
index 4b3a2e0cb7..305e511fea 100644
--- a/src/test/regress/expected/matview.out
+++ b/src/test/regress/expected/matview.out
@@ -668,3 +668,86 @@ NOTICE: relation "matview_ine_tab" already exists, skipping
(0 rows)
DROP MATERIALIZED VIEW matview_ine_tab;
+-- test cases for explain/explain analyze refresh materialized view
+CREATE TABLE mv_exp_tbl (a) AS SELECT * FROM generate_series(1, 10);
+CREATE MATERIALIZED VIEW mv_exp (a) AS
+ SELECT * FROM mv_exp_tbl WHERE a > 5;
+EXPLAIN (COSTS OFF)
+ REFRESH MATERIALIZED VIEW mv_exp WITH NO DATA;
+ QUERY PLAN
+------------------------
+ Seq Scan on mv_exp_tbl
+ Filter: (a > 5)
+(2 rows)
+
+REFRESH MATERIALIZED VIEW mv_exp WITH NO DATA;
+EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF)
+ REFRESH MATERIALIZED VIEW mv_exp WITH NO DATA;
+ QUERY PLAN
+-----------------------------------------
+ Seq Scan on mv_exp_tbl (never executed)
+ Filter: (a > 5)
+(2 rows)
+
+SELECT * FROM mv_exp ORDER BY 1; -- ERROR
+ERROR: materialized view "mv_exp" has not been populated
+HINT: Use the REFRESH MATERIALIZED VIEW command.
+EXPLAIN (COSTS OFF)
+ REFRESH MATERIALIZED VIEW mv_exp;
+ QUERY PLAN
+------------------------
+ Seq Scan on mv_exp_tbl
+ Filter: (a > 5)
+(2 rows)
+
+REFRESH MATERIALIZED VIEW mv_exp;
+EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF)
+ REFRESH MATERIALIZED VIEW mv_exp;
+ QUERY PLAN
+------------------------------------------------
+ Seq Scan on mv_exp_tbl (actual rows=5 loops=1)
+ Filter: (a > 5)
+ Rows Removed by Filter: 5
+(3 rows)
+
+SELECT * FROM mv_exp ORDER BY 1; -- OK
+ a
+----
+ 6
+ 7
+ 8
+ 9
+ 10
+(5 rows)
+
+CREATE UNIQUE INDEX ON mv_exp (a);
+EXPLAIN (COSTS OFF)
+ REFRESH MATERIALIZED VIEW CONCURRENTLY mv_exp;
+ QUERY PLAN
+------------------------
+ Seq Scan on mv_exp_tbl
+ Filter: (a > 5)
+(2 rows)
+
+REFRESH MATERIALIZED VIEW CONCURRENTLY mv_exp;
+EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF)
+ REFRESH MATERIALIZED VIEW CONCURRENTLY mv_exp;
+ QUERY PLAN
+------------------------------------------------
+ Seq Scan on mv_exp_tbl (actual rows=5 loops=1)
+ Filter: (a > 5)
+ Rows Removed by Filter: 5
+(3 rows)
+
+SELECT * FROM mv_exp ORDER BY 1; -- OK
+ a
+----
+ 6
+ 7
+ 8
+ 9
+ 10
+(5 rows)
+
+DROP MATERIALIZED VIEW mv_exp;
+DROP TABLE mv_exp_tbl;
diff --git a/src/test/regress/sql/matview.sql b/src/test/regress/sql/matview.sql
index 4a4bd0d6b6..67a45bbde7 100644
--- a/src/test/regress/sql/matview.sql
+++ b/src/test/regress/sql/matview.sql
@@ -287,3 +287,30 @@ EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF)
CREATE MATERIALIZED VIEW IF NOT EXISTS matview_ine_tab AS
SELECT 1 / 0 WITH NO DATA; -- ok
DROP MATERIALIZED VIEW matview_ine_tab;
+
+-- test cases for explain/explain analyze refresh materialized view
+CREATE TABLE mv_exp_tbl (a) AS SELECT * FROM generate_series(1, 10);
+CREATE MATERIALIZED VIEW mv_exp (a) AS
+ SELECT * FROM mv_exp_tbl WHERE a > 5;
+EXPLAIN (COSTS OFF)
+ REFRESH MATERIALIZED VIEW mv_exp WITH NO DATA;
+REFRESH MATERIALIZED VIEW mv_exp WITH NO DATA;
+EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF)
+ REFRESH MATERIALIZED VIEW mv_exp WITH NO DATA;
+SELECT * FROM mv_exp ORDER BY 1; -- ERROR
+EXPLAIN (COSTS OFF)
+ REFRESH MATERIALIZED VIEW mv_exp;
+REFRESH MATERIALIZED VIEW mv_exp;
+EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF)
+ REFRESH MATERIALIZED VIEW mv_exp;
+SELECT * FROM mv_exp ORDER BY 1; -- OK
+CREATE UNIQUE INDEX ON mv_exp (a);
+EXPLAIN (COSTS OFF)
+ REFRESH MATERIALIZED VIEW CONCURRENTLY mv_exp;
+REFRESH MATERIALIZED VIEW CONCURRENTLY mv_exp;
+EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF)
+ REFRESH MATERIALIZED VIEW CONCURRENTLY mv_exp;
+SELECT * FROM mv_exp ORDER BY 1; -- OK
+
+DROP MATERIALIZED VIEW mv_exp;
+DROP TABLE mv_exp_tbl;
--
2.25.1
