NAME
SET ADD TABLE - Add a table to a Slony-I replication set
SYNOPSIS
SET ADD TABLE (options);
DESCRIPTION
Add an existing user table to a replication set. The set cannot
currently be subscribed by any other node - that functionality is
supported by the SLONIK MERGE SET(7) command.
SET ID = ival
ID of the set to which the table is to be added.
ORIGIN = ival
Origin node for the set. We might imagine a future version of
slonik figuring out this information by itself, but there do lie
race conditions, there.
ID = ival
Unique ID of the table. These ID’s are not only used to uniquely
identify the individual table within the replication system. The
numeric value of this ID also determines the order in which the
tables are locked in a SLONIK LOCK SET(7) command for example.
So these numbers might represent any applicable table hierarchy
to make sure the slonik command scripts do not deadlock at any
critical moment.
This ID must be unique across all sets; you cannot have two
tables in the same cluster with the same ID.
Note that Slony-I generates an in-memory array indicating all of
the fully qualified table names; if you use large table ID
numbers, the sparsely-utilized array can lead to substantial
wastage of memory. Each potential table ID consumes a pointer to
a char, commonly costing 4 bytes per table ID on 32 bit
architectures, and 8 bytes per table ID on 64 bit architectures.
FULLY QUALIFIED NAME = ’string’
The full table name as described in SLONIK TABLE ADD KEY(7).
KEY = { ’string’ | SERIAL }
(Optional) The index name that covers the unique and not null
set of columns to be used as the row identifier for replication
purposes. Or the keyword SERIAL to use the special column added
with a previous SLONIK TABLE ADD KEY(7) command. Default is to
use the table’s primary key. The index name is not fully
qualified; you must omit the namespace.
COMMENT = ’string’
A descriptive text added to the table entry.
This uses “schemadocsetaddtable( integer, integer, text, name, text )”
[not available as a man page].
EXAMPLE
SET ADD TABLE (
SET ID = 1,
ORIGIN = 1,
ID = 20,
FULLY QUALIFIED NAME = ’public.tracker_ticket’,
COMMENT = ’Support ticket’
);
ERROR MESSAGES
Here are some of the error messages you may encounter if adding tables
incorrectly:
Slony-I: setAddTable_int: table public.my_table PK column id nullable
Primary keys (or candidates thereof) are required to have all
column defined as NOT NULL. If you have a PK candidate that has
columns that are not thus restricted, Slony-I will reject the
table with this message.
Slony-I: setAddTable_int: table id 14 has already been assigned!
The table id, stored in sl_table.tab_id, is required to be
unique across all tables/nodes/sets. Apparently you have tried
to reused a table ID.
Slony-I: setAddTable_int(): table public.my_table has no index
mt_idx_14
This will normally occur with candidate primary keys; apparently
the index specified is not available on this node.
Slony-I: setAddTable_int(): table public.my_table not found
Worse than an index missing, the whole table is missing.
Apparently whatever process you were using to get the schema
into place everywhere didn’t work properly.
Slony-I: setAddTable_int(): public.my_view is not a regular table
You can only replicate (at least, using SET ADD TABLE) objects
that are ordinary tables. That doesn’t include views or indexes.
(Indexes can come along for the ride, but you don’t ask to
replicate an index...)
Slony-I: setAddTable_int(): set 4 not found
You need to define a replication set before assigning tables to
it.
Slony-I: setAddTable(): set 4 has remote origin
This will occur if set 4 is configured with, as origin, node 1,
and then you submit a SET ADD TABLE request involving that set
to some other node than node 1. This would be expected to occur
if there was some confusion in the admin conninfo configuration
in the slonik script preamble...
Slony-I: cannot add table to currently subscribed set 1
Slony-I does not support adding tables to sets that are already
participating in subscriptions. Instead, you need to define a
new replication set, and add any new tables to that set. You
might then use SLONIK MERGE SET(7) to merge the new set into an
existing one, if that seems appropriate.
LOCKING BEHAVIOUR
On the origin node, this operation requires a brief exclusive lock on
the table in order to alter it to add the replication trigger. On
subscriber nodes, corresponding locking takes place at the time of the
SUBSCRIBE_SET event.
VERSION INFORMATION
This command was introduced in Slony-I 1.0
12 May 2010 SLONIK SET ADD TABLE(7)