Note PostgreSQL OID synchronization

Previously studied PostgreSQL's notes

CREATE TABLE consumption OID

• < Span style= "Font-family:microsoft Yahei;" > create table My_ test_table, He's going to consume a
• < Span style= "Font-family:microsoft Yahei;" > pg_type insert two records _my_ test_table my_test_table oid
• If the table requires Toast will generate a change in the Toast Tables and Toast Index The table consumes another two, and the viewing process is as follows:
• CREATE TABLE my_test_table (a int, b char (8192));
• Select OID, relname from Pg_class where relname= ' my_test_table ';
• --oid = 16384
• Select OID, relname from Pg_class where relname like '%16384% ';
• Select Typname, oid from Pg_type where typname like '%my_test_table ';

OID Synchronization Process

oid synchronization reason: Span style= "color: #ff0000;" When you create objects such as tables, views, functions, and so on, objects need to be assigned a new oid oid all

Bureau only , so to get one of the largest OIDson all coordinator and datanode . Take CREATE table For example,

The specific process is as follows:

1 ) First and all dn and other than their own co establish the connection.

2 oid request, receive the requested node, put the largest oid sent to coordinator

3 ) Span lang= "en-US" > oid oid setnextassignobjectid

co node next to be assigned oid

4 ) then execute create statement, struct createstmt members tableoidinfo used to store the largest

that gets.

OID , the current Coordiator The query plan is distributed to other nodes, and the other nodes get the maximum OID Call function after

Heap_create_with_catalog , create a table on your own node

OID system tables involved in synchronization

Pg_class

Pg_namespace--create Schema

Pg_constraint

Pg_operator

Pg_ts_parser

Pg_ts_dict

Pg_ts_template

Pg_ts_config

Pg_collation

Pg_am

Pg_extension

Pg_foreign_data_wrapper

Pg_foreign_server

Pg_user_mapping

Pg_type

Pg_enum

Pg_proc

Pg_rewrite

Pg_trigger

Pg_language

Pg_conversion

Pg_cast

Pg_opfamily

Pg_opclass

Pg_tablespace

OID Synchronous Removal

There may be a problem with the current implementation when there are nodes or all nodes OID wrapping up, creating objects is very likely to fail. OID sync Removal Reference

PG-XL , send the object name in the query plan, and then go to the local OID .

Note PostgreSQL OID synchronization