START_TRANSACTION (7)
Leading comments
Title: START TRANSACTION Author: The PostgreSQL Global Development Group Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/> Date: 2017 Manual: PostgreSQL 9.6.5 Documentation Source: PostgreSQL 9.6.5 Language: English
NAME
START_TRANSACTION - start a transaction blockSYNOPSIS
START TRANSACTION [ transaction_mode [, ...] ] where transaction_mode is one of: ISOLATION LEVEL { SERIALIZABLE | REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED } READ WRITE | READ ONLY [ NOT ] DEFERRABLE
DESCRIPTION
This command begins a new transaction block. If the isolation level, read/write mode, or deferrable mode is specified, the new transaction has those characteristics, as if SET TRANSACTION (SET_TRANSACTION(7)) was executed. This is the same as the BEGIN(7) command.
PARAMETERS
Refer to SET TRANSACTION (SET_TRANSACTION(7)) for information on the meaning of the parameters to this statement.
COMPATIBILITY
In the standard, it is not necessary to issue START TRANSACTION to start a transaction block: any SQL command implicitly begins a block. PostgreSQL's behavior can be seen as implicitly issuing a COMMIT after each command that does not follow START TRANSACTION (or BEGIN), and it is therefore often called lqautocommitrq. Other relational database systems might offer an autocommit feature as a convenience.
The DEFERRABLE transaction_mode is a PostgreSQL language extension.
The SQL standard requires commas between successive transaction_modes, but for historical reasons PostgreSQL allows the commas to be omitted.
See also the compatibility section of SET TRANSACTION (SET_TRANSACTION(7)).