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Allow specifying column lists for logical replication

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This allows specifying an optional column list when adding a table to
logical replication. The column list may be specified after the table
name, enclosed in parentheses. Columns not included in this list are not
sent to the subscriber, allowing the schema on the subscriber to be a
subset of the publisher schema.

For UPDATE/DELETE publications, the column list needs to cover all
REPLICA IDENTITY columns. For INSERT publications, the column list is
arbitrary and may omit some REPLICA IDENTITY columns. Furthermore, if
the table uses REPLICA IDENTITY FULL, column list is not allowed.

The column list can contain only simple column references. Complex
expressions, function calls etc. are not allowed. This restriction could
be relaxed in the future.

During the initial table synchronization, only columns included in the
column list are copied to the subscriber. If the subscription has
several publications, containing the same table with different column
lists, columns specified in any of the lists will be copied.

This means all columns are replicated if the table has no column list
at all (which is treated as column list with all columns), or when of
the publications is defined as FOR ALL TABLES (possibly IN SCHEMA that
matches the schema of the table).

For partitioned tables, publish_via_partition_root determines whether
the column list for the root or the leaf relation will be used. If the
parameter is 'false' (the default), the list defined for the leaf
relation is used. Otherwise, the column list for the root partition
will be used.

Psql commands \dRp+ and \d <table-name> now display any column lists.

Author: Tomas Vondra, Alvaro Herrera, Rahila Syed
Reviewed-by: Peter Eisentraut, Alvaro Herrera, Vignesh C, Ibrar Ahmed,
Amit Kapila, Hou zj, Peter Smith, Wang wei, Tang, Shi yu
Discussion: https://postgr.es/m/CAH2L28vddB_NFdRVpuyRBJEBWjz4BSyTB=_ektNRH8NJ1jf95g@mail.gmail.com
This commit is contained in:
Tomas Vondra
2022-03-26 00:45:21 +01:00
parent 05843b1aa4
commit 923def9a53
26 changed files with 2833 additions and 92 deletions
Download Patch File Download Diff File Expand all files Collapse all files

61
src/backend/replication/logical/proto.c
View File

@@ -29,16 +29,30 @@
#define TRUNCATE_CASCADE (1<<0)
#define TRUNCATE_RESTART_SEQS (1<<1)
static void logicalrep_write_attrs(StringInfo out, Relation rel);
static void logicalrep_write_attrs(StringInfo out, Relation rel,
Bitmapset *columns);
static void logicalrep_write_tuple(StringInfo out, Relation rel,
TupleTableSlot *slot,
bool binary);
bool binary, Bitmapset *columns);
static void logicalrep_read_attrs(StringInfo in, LogicalRepRelation *rel);
static void logicalrep_read_tuple(StringInfo in, LogicalRepTupleData *tuple);
static void logicalrep_write_namespace(StringInfo out, Oid nspid);
static const char *logicalrep_read_namespace(StringInfo in);
/*
* Check if a column is covered by a column list.
*
* Need to be careful about NULL, which is treated as a column list covering
* all columns.
*/
static bool
column_in_column_list(int attnum, Bitmapset *columns)
{
return (columns == NULL || bms_is_member(attnum, columns));
}
/*
* Write BEGIN to the output stream.
*/
@@ -398,7 +412,7 @@ logicalrep_read_origin(StringInfo in, XLogRecPtr *origin_lsn)
*/
void
logicalrep_write_insert(StringInfo out, TransactionId xid, Relation rel,
TupleTableSlot *newslot, bool binary)
TupleTableSlot *newslot, bool binary, Bitmapset *columns)
{
pq_sendbyte(out, LOGICAL_REP_MSG_INSERT);
@@ -410,7 +424,7 @@ logicalrep_write_insert(StringInfo out, TransactionId xid, Relation rel,
pq_sendint32(out, RelationGetRelid(rel));
pq_sendbyte(out, 'N'); /* new tuple follows */
logicalrep_write_tuple(out, rel, newslot, binary);
logicalrep_write_tuple(out, rel, newslot, binary, columns);
}
/*
@@ -443,7 +457,7 @@ logicalrep_read_insert(StringInfo in, LogicalRepTupleData *newtup)
void
logicalrep_write_update(StringInfo out, TransactionId xid, Relation rel,
TupleTableSlot *oldslot, TupleTableSlot *newslot,
bool binary)
bool binary, Bitmapset *columns)
{
pq_sendbyte(out, LOGICAL_REP_MSG_UPDATE);
@@ -464,11 +478,11 @@ logicalrep_write_update(StringInfo out, TransactionId xid, Relation rel,
pq_sendbyte(out, 'O'); /* old tuple follows */
else
pq_sendbyte(out, 'K'); /* old key follows */
logicalrep_write_tuple(out, rel, oldslot, binary);
logicalrep_write_tuple(out, rel, oldslot, binary, NULL);
}
pq_sendbyte(out, 'N'); /* new tuple follows */
logicalrep_write_tuple(out, rel, newslot, binary);
logicalrep_write_tuple(out, rel, newslot, binary, columns);
}
/*
@@ -537,7 +551,7 @@ logicalrep_write_delete(StringInfo out, TransactionId xid, Relation rel,
else
pq_sendbyte(out, 'K'); /* old key follows */
logicalrep_write_tuple(out, rel, oldslot, binary);
logicalrep_write_tuple(out, rel, oldslot, binary, NULL);
}
/*
@@ -702,7 +716,8 @@ logicalrep_read_sequence(StringInfo in, LogicalRepSequence *seqdata)
* Write relation description to the output stream.
*/
void
logicalrep_write_rel(StringInfo out, TransactionId xid, Relation rel)
logicalrep_write_rel(StringInfo out, TransactionId xid, Relation rel,
Bitmapset *columns)
{
char *relname;
@@ -724,7 +739,7 @@ logicalrep_write_rel(StringInfo out, TransactionId xid, Relation rel)
pq_sendbyte(out, rel->rd_rel->relreplident);
/* send the attribute info */
logicalrep_write_attrs(out, rel);
logicalrep_write_attrs(out, rel, columns);
}
/*
@@ -801,7 +816,7 @@ logicalrep_read_typ(StringInfo in, LogicalRepTyp *ltyp)
*/
static void
logicalrep_write_tuple(StringInfo out, Relation rel, TupleTableSlot *slot,
bool binary)
bool binary, Bitmapset *columns)
{
TupleDesc desc;
Datum *values;
@@ -813,8 +828,14 @@ logicalrep_write_tuple(StringInfo out, Relation rel, TupleTableSlot *slot,
for (i = 0; i < desc->natts; i++)
{
if (TupleDescAttr(desc, i)->attisdropped || TupleDescAttr(desc, i)->attgenerated)
Form_pg_attribute att = TupleDescAttr(desc, i);
if (att->attisdropped || att->attgenerated)
continue;
if (!column_in_column_list(att->attnum, columns))
continue;
nliveatts++;
}
pq_sendint16(out, nliveatts);
@@ -833,6 +854,9 @@ logicalrep_write_tuple(StringInfo out, Relation rel, TupleTableSlot *slot,
if (att->attisdropped || att->attgenerated)
continue;
if (!column_in_column_list(att->attnum, columns))
continue;
if (isnull[i])
{
pq_sendbyte(out, LOGICALREP_COLUMN_NULL);
@@ -954,7 +978,7 @@ logicalrep_read_tuple(StringInfo in, LogicalRepTupleData *tuple)
* Write relation attribute metadata to the stream.
*/
static void
logicalrep_write_attrs(StringInfo out, Relation rel)
logicalrep_write_attrs(StringInfo out, Relation rel, Bitmapset *columns)
{
TupleDesc desc;
int i;
@@ -967,8 +991,14 @@ logicalrep_write_attrs(StringInfo out, Relation rel)
/* send number of live attributes */
for (i = 0; i < desc->natts; i++)
{
if (TupleDescAttr(desc, i)->attisdropped || TupleDescAttr(desc, i)->attgenerated)
Form_pg_attribute att = TupleDescAttr(desc, i);
if (att->attisdropped || att->attgenerated)
continue;
if (!column_in_column_list(att->attnum, columns))
continue;
nliveatts++;
}
pq_sendint16(out, nliveatts);
@@ -987,6 +1017,9 @@ logicalrep_write_attrs(StringInfo out, Relation rel)
if (att->attisdropped || att->attgenerated)
continue;
if (!column_in_column_list(att->attnum, columns))
continue;
/* REPLICA IDENTITY FULL means all columns are sent as part of key. */
if (replidentfull ||
bms_is_member(att->attnum - FirstLowInvalidHeapAttributeNumber,