---
name: "START_TRANSACTION"
section: "7"
platform: "linux"
package: "postgresql"
version: "18.6-4"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/START_TRANSACTION"
---

# START\_TRANSACTION(7)

start a transaction block

## NAME

START\_TRANSACTION - start a transaction block

## SYNOPSIS

```
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** was executed. This is the same as the **BEGIN** command.

## PARAMETERS

Refer to SET TRANSACTION ([**SET\_TRANSACTION**(7)](/SET_TRANSACTION/7.md)) 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 “autocommit”. 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)](/SET_TRANSACTION/7.md)).

## SEE ALSO

[**BEGIN**(7)](/BEGIN/7.md), [**COMMIT**(7)](/COMMIT/7.md), [**ROLLBACK**(7)](/ROLLBACK/7.md), [**SAVEPOINT**(7)](/SAVEPOINT/7.md), SET TRANSACTION ([**SET\_TRANSACTION**(7)](/SET_TRANSACTION/7.md))