The view pg_prepared_xacts displays information about transactions that are currently prepared for two-phase commit (see
PREPARE TRANSACTION
for details).
pg_prepared_xacts contains one row per prepared transaction. An entry is removed when the transaction is committed or rolled back.
Table 42-38. pg_prepared_xacts Columns
| Name |
Type |
References |
Description |
|
transaction
|
xid
|
|
Numeric transaction identifier of the prepared transaction |
|
gid
|
text
|
|
Global transaction identifier that was assigned to the transaction |
|
prepared
|
timestamp with time zone
|
|
Time at which the transaction was prepared for commit |
|
owner
|
name
|
pg_authid
.rolname
|
Name of the user that executed the transaction |
|
database
|
name
|
pg_database
.datname
|
Name of the database in which the transaction was executed |
When the pg_prepared_xacts view is accessed, the internal transaction manager data structures are momentarily locked, and a copy is made for the view to display. This ensures that the view produces a consistent set of results, while not blocking normal operations longer than necessary. Nonetheless there could be some impact on database performance if this view is read often.
