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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

33
src/backend/parser/gram.y
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@ -9749,13 +9749,14 @@ CreatePublicationStmt:
* relation_expr here.
*/
PublicationObjSpec:
TABLE relation_expr OptWhereClause
TABLE relation_expr opt_column_list OptWhereClause
{
$$ = makeNode(PublicationObjSpec);
$$->pubobjtype = PUBLICATIONOBJ_TABLE;
$$->pubtable = makeNode(PublicationTable);
$$->pubtable->relation = $2;
$$->pubtable->whereClause = $3;
$$->pubtable->columns = $3;
$$->pubtable->whereClause = $4;
}
| ALL TABLES IN_P SCHEMA ColId
{
@ -9790,11 +9791,15 @@ PublicationObjSpec:
$$->pubobjtype = PUBLICATIONOBJ_SEQUENCES_IN_CUR_SCHEMA;
$$->location = @5;
}
| ColId OptWhereClause
| ColId opt_column_list OptWhereClause
{
$$ = makeNode(PublicationObjSpec);
$$->pubobjtype = PUBLICATIONOBJ_CONTINUATION;
if ($2)
/*
* If either a row filter or column list is specified, create
* a PublicationTable object.
*/
if ($2 || $3)
{
/*
* The OptWhereClause must be stored here but it is
@ -9804,7 +9809,8 @@ PublicationObjSpec:
*/
$$->pubtable = makeNode(PublicationTable);
$$->pubtable->relation = makeRangeVar(NULL, $1, @1);
$$->pubtable->whereClause = $2;
$$->pubtable->columns = $2;
$$->pubtable->whereClause = $3;
}
else
{
@ -9812,23 +9818,25 @@ PublicationObjSpec:
}
$$->location = @1;
}
| ColId indirection OptWhereClause
| ColId indirection opt_column_list OptWhereClause
{
$$ = makeNode(PublicationObjSpec);
$$->pubobjtype = PUBLICATIONOBJ_CONTINUATION;
$$->pubtable = makeNode(PublicationTable);
$$->pubtable->relation = makeRangeVarFromQualifiedName($1, $2, @1, yyscanner);
$$->pubtable->whereClause = $3;
$$->pubtable->columns = $3;
$$->pubtable->whereClause = $4;
$$->location = @1;
}
/* grammar like tablename * , ONLY tablename, ONLY ( tablename ) */
| extended_relation_expr OptWhereClause
| extended_relation_expr opt_column_list OptWhereClause
{
$$ = makeNode(PublicationObjSpec);
$$->pubobjtype = PUBLICATIONOBJ_CONTINUATION;
$$->pubtable = makeNode(PublicationTable);
$$->pubtable->relation = $1;
$$->pubtable->whereClause = $2;
$$->pubtable->columns = $2;
$$->pubtable->whereClause = $3;
}
| CURRENT_SCHEMA
{
@ -17524,6 +17532,13 @@ preprocess_pubobj_list(List *pubobjspec_list, core_yyscan_t yyscanner)
errmsg("WHERE clause not allowed for schema"),
parser_errposition(pubobj->location));
/* Column list is not allowed on a schema object */
if (pubobj->pubtable && pubobj->pubtable->columns)
ereport(ERROR,
errcode(ERRCODE_SYNTAX_ERROR),
errmsg("column specification not allowed for schema"),
parser_errposition(pubobj->location));
/*
* We can distinguish between the different type of schema
* objects based on whether name and pubtable is set.