<para>
The optional <literal>WITH</literal> clause specifies <firstterm>storage
parameters</firstterm> for the index. Each index method has its own set of allowed
- storage parameters. The B-tree, hash, GiST and SP-GiST index methods all
- accept this parameter:
+ storage parameters. All indexes accept the following parameter:
+ </para>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>recheck_on_update</literal></term>
+ <listitem>
+ <para>
+ Specifies whether to recheck a functional index value to see whether
+ we can use a HOT update or not. The default value is on for functional
+ indexes with an total expression cost less than 1000, otherwise off.
+ You might decide to turn this off if you knew that a function used in
+ an index is unlikely to return the same value when one of the input
+ columns is updated and so the recheck is not worth the additional cost
+ of executing the function.
+ </para>
+
+ <para>
+ Functional indexes are used frequently for the case where the function
+ returns a subset of the argument. Examples of this would be accessing
+ part of a string with <literal>SUBSTR()</literal> or accessing a single
+ field in a JSON document using an expression such as
+ <literal>(bookinfo->>'isbn')</literal>. In this example, the JSON
+ document might be updated frequently, yet it is uncommon for the ISBN
+ field for a book to change so we would keep the parameter set to on
+ for that index. A more frequently changing field might have an index
+ with this parameter turned off, while very frequently changing fields
+ might be better to avoid indexing at all under high load.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+
+ <para>
+ The B-tree, hash, GiST and SP-GiST index methods all accept this parameter:
</para>
<variablelist>
},
true
},
+ {
+ {
+ "recheck_on_update",
+ "Recheck functional index expression for changed value after update",
+ RELOPT_KIND_INDEX,
+ ShareUpdateExclusiveLock /* since only applies to later UPDATEs */
+ },
+ true
+ },
{
{
"security_barrier",
break;
}
}
- if (validate && !found)
+ if (validate && !found && options[i].gen->kinds != RELOPT_KIND_INDEX)
elog(ERROR, "reloption \"%s\" not found in parse table",
options[i].gen->name);
}
return amoptions(reloptions, validate);
}
+/*
+ * Parse generic options for all indexes.
+ *
+ * reloptions options as text[] datum
+ * validate error flag
+ */
+bytea *
+index_generic_reloptions(Datum reloptions, bool validate)
+{
+ int numoptions;
+ GenericIndexOpts *idxopts;
+ relopt_value *options;
+ static const relopt_parse_elt tab[] = {
+ {"recheck_on_update", RELOPT_TYPE_BOOL, offsetof(GenericIndexOpts, recheck_on_update)}
+ };
+
+ options = parseRelOptions(reloptions, validate,
+ RELOPT_KIND_INDEX,
+ &numoptions);
+
+ /* if none set, we're done */
+ if (numoptions == 0)
+ return NULL;
+
+ idxopts = allocateReloptStruct(sizeof(GenericIndexOpts), options, numoptions);
+
+ fillRelOptions((void *)idxopts, sizeof(GenericIndexOpts), options, numoptions,
+ validate, tab, lengthof(tab));
+
+ pfree(options);
+
+ return (bytea*) idxopts;
+}
+
/*
* Option parser for attribute reloptions
*/
#include "access/xlogutils.h"
#include "catalog/catalog.h"
#include "catalog/namespace.h"
+#include "catalog/index.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "port/atomics.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/tqual.h"
-
+#include "utils/memutils.h"
+#include "nodes/execnodes.h"
+#include "executor/executor.h"
/* GUC variable */
bool synchronize_seqscans = true;
static XLogRecPtr log_heap_new_cid(Relation relation, HeapTuple tup);
static HeapTuple ExtractReplicaIdentity(Relation rel, HeapTuple tup, bool key_modified,
bool *copy);
+static bool ProjIndexIsUnchanged(Relation relation, HeapTuple oldtup, HeapTuple newtup);
/*
HTSU_Result result;
TransactionId xid = GetCurrentTransactionId();
Bitmapset *hot_attrs;
+ Bitmapset *proj_idx_attrs;
Bitmapset *key_attrs;
Bitmapset *id_attrs;
Bitmapset *interesting_attrs;
* Note that we get copies of each bitmap, so we need not worry about
* relcache flush happening midway through.
*/
- hot_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_ALL);
+ hot_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_HOT);
+ proj_idx_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_PROJ);
key_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_KEY);
id_attrs = RelationGetIndexAttrBitmap(relation,
INDEX_ATTR_BITMAP_IDENTITY_KEY);
-
-
block = ItemPointerGetBlockNumber(otid);
buffer = ReadBuffer(relation, block);
page = BufferGetPage(buffer);
if (!PageIsFull(page))
{
interesting_attrs = bms_add_members(interesting_attrs, hot_attrs);
+ interesting_attrs = bms_add_members(interesting_attrs, proj_idx_attrs);
hot_attrs_checked = true;
}
interesting_attrs = bms_add_members(interesting_attrs, key_attrs);
if (vmbuffer != InvalidBuffer)
ReleaseBuffer(vmbuffer);
bms_free(hot_attrs);
+ bms_free(proj_idx_attrs);
bms_free(key_attrs);
bms_free(id_attrs);
bms_free(modified_attrs);
/*
* Since the new tuple is going into the same page, we might be able
* to do a HOT update. Check if any of the index columns have been
- * changed. If the page was already full, we may have skipped checking
- * for index columns. If so, HOT update is possible.
+ * changed, or if we have projection functional indexes, check whether
+ * the old and the new values are the same. If the page was already
+ * full, we may have skipped checking for index columns. If so, HOT
+ * update is possible.
*/
- if (hot_attrs_checked && !bms_overlap(modified_attrs, hot_attrs))
+ if (hot_attrs_checked
+ && !bms_overlap(modified_attrs, hot_attrs)
+ && (!bms_overlap(modified_attrs, proj_idx_attrs)
+ || ProjIndexIsUnchanged(relation, &oldtup, newtup)))
+ {
use_hot_update = true;
+ }
}
else
{
heap_freetuple(old_key_tuple);
bms_free(hot_attrs);
+ bms_free(proj_idx_attrs);
bms_free(key_attrs);
bms_free(id_attrs);
bms_free(modified_attrs);
}
}
+/*
+ * Check whether the value is unchanged after update of a projection
+ * functional index. Compare the new and old values of the indexed
+ * expression to see if we are able to use a HOT update or not.
+ */
+static bool ProjIndexIsUnchanged(Relation relation, HeapTuple oldtup, HeapTuple newtup)
+{
+ ListCell *l;
+ List *indexoidlist = RelationGetIndexList(relation);
+ EState *estate = CreateExecutorState();
+ ExprContext *econtext = GetPerTupleExprContext(estate);
+ TupleTableSlot *slot = MakeSingleTupleTableSlot(RelationGetDescr(relation));
+ bool equals = true;
+ Datum old_values[INDEX_MAX_KEYS];
+ bool old_isnull[INDEX_MAX_KEYS];
+ Datum new_values[INDEX_MAX_KEYS];
+ bool new_isnull[INDEX_MAX_KEYS];
+ int indexno = 0;
+ econtext->ecxt_scantuple = slot;
+
+ foreach(l, indexoidlist)
+ {
+ if (bms_is_member(indexno, relation->rd_projidx))
+ {
+ Oid indexOid = lfirst_oid(l);
+ Relation indexDesc = index_open(indexOid, AccessShareLock);
+ IndexInfo *indexInfo = BuildIndexInfo(indexDesc);
+ int i;
+
+ ResetExprContext(econtext);
+ ExecStoreTuple(oldtup, slot, InvalidBuffer, false);
+ FormIndexDatum(indexInfo,
+ slot,
+ estate,
+ old_values,
+ old_isnull);
+
+ ExecStoreTuple(newtup, slot, InvalidBuffer, false);
+ FormIndexDatum(indexInfo,
+ slot,
+ estate,
+ new_values,
+ new_isnull);
+
+ for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
+ {
+ if (old_isnull[i] != new_isnull[i])
+ {
+ equals = false;
+ break;
+ }
+ else if (!old_isnull[i])
+ {
+ Form_pg_attribute att = TupleDescAttr(RelationGetDescr(indexDesc), i);
+ if (!datumIsEqual(old_values[i], new_values[i], att->attbyval, att->attlen))
+ {
+ equals = false;
+ break;
+ }
+ }
+ }
+ index_close(indexDesc, AccessShareLock);
+
+ if (!equals)
+ {
+ break;
+ }
+ }
+ indexno += 1;
+ }
+ ExecDropSingleTupleTableSlot(slot);
+ FreeExecutorState(estate);
+
+ return equals;
+}
+
+
/*
* Check which columns are being updated.
*
#include "access/amapi.h"
#include "access/multixact.h"
#include "access/relscan.h"
+#include "access/reloptions.h"
#include "access/sysattr.h"
#include "access/transam.h"
#include "access/visibilitymap.h"
/* Ensure rd_indexattr is valid; see comments for RelationSetIndexList */
if (is_pg_class)
- (void) RelationGetIndexAttrBitmap(rel, INDEX_ATTR_BITMAP_ALL);
+ (void) RelationGetIndexAttrBitmap(rel, INDEX_ATTR_BITMAP_HOT);
PG_TRY();
{
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
+#include "optimizer/cost.h"
#include "optimizer/prep.h"
#include "optimizer/var.h"
+#include "pgstat.h"
#include "rewrite/rewriteDefine.h"
#include "rewrite/rowsecurity.h"
#include "storage/lmgr.h"
list_free_deep(relation->rd_fkeylist);
list_free(relation->rd_indexlist);
bms_free(relation->rd_indexattr);
+ bms_free(relation->rd_projindexattr);
bms_free(relation->rd_keyattr);
bms_free(relation->rd_pkattr);
bms_free(relation->rd_idattr);
+ bms_free(relation->rd_projidx);
if (relation->rd_pubactions)
pfree(relation->rd_pubactions);
if (relation->rd_options)
return result;
}
+#define HEURISTIC_MAX_HOT_RECHECK_EXPR_COST 1000
+
+/*
+ * Check if functional index is projection: index expression returns some subset
+ * of its argument values. During HOT update check we handle projection indexes
+ * differently: instead of checking if any of attributes used in indexed
+ * expression were updated, we calculate and compare values of index expression
+ * for old and new tuple values.
+ *
+ * Decision made by this function is based on two sources:
+ * 1. Calculated cost of index expression: if greater than some heuristic limit
+ then extra comparison of index expression values is expected to be too
+ expensive, so we don't attempt it by default.
+ * 2. "recheck_on_update" index option explicitly set by user, which overrides 1)
+ */
+static bool IsProjectionFunctionalIndex(Relation index, IndexInfo* ii)
+{
+ bool is_projection = false;
+
+ if (ii->ii_Expressions)
+ {
+ HeapTuple tuple;
+ Datum reloptions;
+ bool isnull;
+ QualCost index_expr_cost;
+
+ /* by default functional index is considered as non-injective */
+ is_projection = true;
+
+ cost_qual_eval(&index_expr_cost, ii->ii_Expressions, NULL);
+
+ /*
+ * If index expression is too expensive, then disable projection
+ * optimization, because extra evaluation of index expression is
+ * expected to be more expensive than index update. Currently the
+ * projection optimization has to calculate index expression twice
+ * when the value of index expression has not changed and three times
+ * when values differ because the expression is recalculated when
+ * inserting a new index entry for the changed value.
+ */
+ if ((index_expr_cost.startup + index_expr_cost.per_tuple) >
+ HEURISTIC_MAX_HOT_RECHECK_EXPR_COST)
+ is_projection = false;
+
+ tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(RelationGetRelid(index)));
+ if (!HeapTupleIsValid(tuple))
+ elog(ERROR, "cache lookup failed for relation %u", RelationGetRelid(index));
+
+ reloptions = SysCacheGetAttr(RELOID, tuple,
+ Anum_pg_class_reloptions, &isnull);
+ if (!isnull)
+ {
+ GenericIndexOpts *idxopts;
+
+ idxopts = (GenericIndexOpts *) index_generic_reloptions(reloptions, false);
+
+ if (idxopts != NULL)
+ {
+ is_projection = idxopts->recheck_on_update;
+ pfree(idxopts);
+ }
+ }
+ ReleaseSysCache(tuple);
+ }
+ return is_projection;
+}
+
/*
* RelationGetIndexAttrBitmap -- get a bitmap of index attribute numbers
*
Bitmapset *
RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
{
- Bitmapset *indexattrs; /* indexed columns */
+ Bitmapset *indexattrs; /* columns used in non-projection indexes */
+ Bitmapset *projindexattrs; /* columns used in projection indexes */
Bitmapset *uindexattrs; /* columns in unique indexes */
Bitmapset *pkindexattrs; /* columns in the primary index */
Bitmapset *idindexattrs; /* columns in the replica identity */
+ Bitmapset *projindexes; /* projection indexes */
List *indexoidlist;
List *newindexoidlist;
Oid relpkindex;
Oid relreplindex;
ListCell *l;
MemoryContext oldcxt;
+ int indexno;
/* Quick exit if we already computed the result. */
if (relation->rd_indexattr != NULL)
{
switch (attrKind)
{
- case INDEX_ATTR_BITMAP_ALL:
+ case INDEX_ATTR_BITMAP_HOT:
return bms_copy(relation->rd_indexattr);
+ case INDEX_ATTR_BITMAP_PROJ:
+ return bms_copy(relation->rd_projindexattr);
case INDEX_ATTR_BITMAP_KEY:
return bms_copy(relation->rd_keyattr);
case INDEX_ATTR_BITMAP_PRIMARY_KEY:
* won't be returned at all by RelationGetIndexList.
*/
indexattrs = NULL;
+ projindexattrs = NULL;
uindexattrs = NULL;
pkindexattrs = NULL;
idindexattrs = NULL;
+ projindexes = NULL;
+ indexno = 0;
foreach(l, indexoidlist)
{
Oid indexOid = lfirst_oid(l);
}
}
- /* Collect all attributes used in expressions, too */
- pull_varattnos((Node *) indexInfo->ii_Expressions, 1, &indexattrs);
-
+ /* Collect attributes used in expressions, too */
+ if (IsProjectionFunctionalIndex(indexDesc, indexInfo))
+ {
+ projindexes = bms_add_member(projindexes, indexno);
+ pull_varattnos((Node *) indexInfo->ii_Expressions, 1, &projindexattrs);
+ }
+ else
+ {
+ /* Collect all attributes used in expressions, too */
+ pull_varattnos((Node *) indexInfo->ii_Expressions, 1, &indexattrs);
+ }
/* Collect all attributes in the index predicate, too */
pull_varattnos((Node *) indexInfo->ii_Predicate, 1, &indexattrs);
index_close(indexDesc, AccessShareLock);
+ indexno += 1;
}
/*
bms_free(pkindexattrs);
bms_free(idindexattrs);
bms_free(indexattrs);
+ bms_free(projindexattrs);
+ bms_free(projindexes);
goto restart;
}
/* Don't leak the old values of these bitmaps, if any */
bms_free(relation->rd_indexattr);
relation->rd_indexattr = NULL;
+ bms_free(relation->rd_projindexattr);
+ relation->rd_projindexattr = NULL;
bms_free(relation->rd_keyattr);
relation->rd_keyattr = NULL;
bms_free(relation->rd_pkattr);
relation->rd_pkattr = NULL;
bms_free(relation->rd_idattr);
relation->rd_idattr = NULL;
+ bms_free(relation->rd_projidx);
+ relation->rd_projidx = NULL;
/*
* Now save copies of the bitmaps in the relcache entry. We intentionally
relation->rd_pkattr = bms_copy(pkindexattrs);
relation->rd_idattr = bms_copy(idindexattrs);
relation->rd_indexattr = bms_copy(indexattrs);
+ relation->rd_projindexattr = bms_copy(projindexattrs);
+ relation->rd_projidx = bms_copy(projindexes);
MemoryContextSwitchTo(oldcxt);
/* We return our original working copy for caller to play with */
switch (attrKind)
{
- case INDEX_ATTR_BITMAP_ALL:
+ case INDEX_ATTR_BITMAP_HOT:
return indexattrs;
+ case INDEX_ATTR_BITMAP_PROJ:
+ return projindexattrs;
case INDEX_ATTR_BITMAP_KEY:
return uindexattrs;
case INDEX_ATTR_BITMAP_PRIMARY_KEY:
rel->rd_pkindex = InvalidOid;
rel->rd_replidindex = InvalidOid;
rel->rd_indexattr = NULL;
+ rel->rd_projindexattr = NULL;
rel->rd_keyattr = NULL;
rel->rd_pkattr = NULL;
rel->rd_idattr = NULL;
+ rel->rd_projidx = NULL;
rel->rd_pubactions = NULL;
rel->rd_statvalid = false;
rel->rd_statlist = NIL;
COMPLETE_WITH_CONST("(");
/* ALTER INDEX <foo> SET|RESET ( */
else if (Matches5("ALTER", "INDEX", MatchAny, "RESET", "("))
- COMPLETE_WITH_LIST6("fillfactor",
+ COMPLETE_WITH_LIST7("fillfactor", "recheck_on_update",
"fastupdate", "gin_pending_list_limit", /* GIN */
"buffering", /* GiST */
"pages_per_range", "autosummarize" /* BRIN */
);
else if (Matches5("ALTER", "INDEX", MatchAny, "SET", "("))
- COMPLETE_WITH_LIST6("fillfactor =",
+ COMPLETE_WITH_LIST7("fillfactor =", "recheck_on_update =",
"fastupdate =", "gin_pending_list_limit =", /* GIN */
"buffering =", /* GiST */
"pages_per_range =", "autosummarize =" /* BRIN */
RELOPT_KIND_PARTITIONED = (1 << 11),
/* if you add a new kind, make sure you update "last_default" too */
RELOPT_KIND_LAST_DEFAULT = RELOPT_KIND_PARTITIONED,
+ RELOPT_KIND_INDEX = RELOPT_KIND_BTREE|RELOPT_KIND_HASH|RELOPT_KIND_GIN|RELOPT_KIND_SPGIST,
/* some compilers treat enums as signed ints, so we can't use 1 << 31 */
RELOPT_KIND_MAX = (1 << 30)
} relopt_kind;
extern bytea *view_reloptions(Datum reloptions, bool validate);
extern bytea *index_reloptions(amoptions_function amoptions, Datum reloptions,
bool validate);
+extern bytea *index_generic_reloptions(Datum reloptions, bool validate);
extern bytea *attribute_reloptions(Datum reloptions, bool validate);
extern bytea *tablespace_reloptions(Datum reloptions, bool validate);
extern LOCKMODE AlterTableGetRelOptionsLockLevel(List *defList);
List *rd_statlist; /* list of OIDs of extended stats */
/* data managed by RelationGetIndexAttrBitmap: */
- Bitmapset *rd_indexattr; /* identifies columns used in indexes */
+ Bitmapset *rd_indexattr; /* columns used in non-projection indexes */
+ Bitmapset *rd_projindexattr; /* columns used in projection indexes */
Bitmapset *rd_keyattr; /* cols that can be ref'd by foreign keys */
Bitmapset *rd_pkattr; /* cols included in primary key */
Bitmapset *rd_idattr; /* included in replica identity index */
+ Bitmapset *rd_projidx; /* Oids of projection indexes */
PublicationActions *rd_pubactions; /* publication actions */
Oid conpfeqop[INDEX_MAX_KEYS]; /* PK = FK operator OIDs */
} ForeignKeyCacheInfo;
+/*
+ * Options common for all all indexes
+ */
+typedef struct GenericIndexOpts
+{
+ int32 vl_len_;
+ bool recheck_on_update;
+} GenericIndexOpts;
/*
* StdRdOptions
typedef enum IndexAttrBitmapKind
{
- INDEX_ATTR_BITMAP_ALL,
+ INDEX_ATTR_BITMAP_HOT,
+ INDEX_ATTR_BITMAP_PROJ,
INDEX_ATTR_BITMAP_KEY,
INDEX_ATTR_BITMAP_PRIMARY_KEY,
INDEX_ATTR_BITMAP_IDENTITY_KEY
--- /dev/null
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name')) with (recheck_on_update=false);
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+drop table keyvalue;
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name')) with (recheck_on_update=true);
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+update keyvalue set info='{"name": "smith", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+update keyvalue set info='{"name": "smith", "data": "some more data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 2
+(1 row)
+
+drop table keyvalue;
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name'));
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+update keyvalue set info='{"name": "smith", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+update keyvalue set info='{"name": "smith", "data": "some more data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 2
+(1 row)
+
+drop table keyvalue;
# ----------
# Another group of parallel tests
# ----------
-test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password
+test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password func_index
# ----------
# Another group of parallel tests
test: arrays
test: btree_index
test: hash_index
+test: func_index
test: update
test: delete
test: namespace
--- /dev/null
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name')) with (recheck_on_update=false);
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+drop table keyvalue;
+
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name')) with (recheck_on_update=true);
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+update keyvalue set info='{"name": "smith", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+update keyvalue set info='{"name": "smith", "data": "some more data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+drop table keyvalue;
+
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name'));
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+update keyvalue set info='{"name": "smith", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+update keyvalue set info='{"name": "smith", "data": "some more data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass);
+drop table keyvalue;
+
+
projects / users / gsingh / postgres.git / commitdiff