Write-Ahead Log / Checkpoints

  • Article

checkpoint_completion_target

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Specifies the target of checkpoint completion, as a fraction of total time between checkpoints.
Data type numeric
Default value 0.9
Allowed values 0-1
Parameter type dynamic
Documentation checkpoint_completion_target

checkpoint_flush_after

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Number of pages after which previously performed writes are flushed to disk.
Data type integer
Default value 32
Allowed values 32
Parameter type read-only
Documentation checkpoint_flush_after

checkpoint_timeout

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum time between automatic WAL checkpoints, in seconds. The valid range is between 30 seconds and one day.
Data type integer
Default value 600
Allowed values 30-86400
Parameter type dynamic
Documentation checkpoint_timeout

checkpoint_warning

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Writes a warning message if checkpoints caused by the filling of WAL segment more frequently than this.
Data type integer
Default value 30
Allowed values 0-2147483647
Parameter type dynamic
Documentation checkpoint_warning

max_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum size to let the WAL grow before triggering automatic checkpoint.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values 32-65536
Parameter type dynamic
Documentation max_wal_size

Azure-specific notes

The default value for the max_wal_size server parameter is calculated when you provision the instance of Azure Database for PostgreSQL flexible server, based on the product name that you select for its compute. Any subsequent changes of product selection to the compute that supports the flexible server won't have any effect on the default value for the max_wal_size server parameter of that instance.

Every time you change the size of the disk assigned to the instance, you should also adjust the value for the max_wal_size parameter according to the values listed in the following table.

The value is computed based on the size of the disk chosen for the instance, as indicated in the following table:

Disks size max_wal_size
32 GiB 2048 MiB
64 GiB 4096 MiB
128 GiB 12288 MiB
256 GiB 20480 MiB
512 GiB 25600 MiB
512 GiB 25600 MiB
1 TiB 30720 MiB
2 TiB 40960 MiB
4 TiB 40960 MiB
8 TiB 65536 MiB
16 TiB 65536 MiB
32 TiB 65536 MiB

min_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Sets the minimum size to shrink the WAL to.
Data type integer
Default value 80
Allowed values 32-2097151
Parameter type dynamic
Documentation min_wal_size

checkpoint_completion_target

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Specifies the target of checkpoint completion, as a fraction of total time between checkpoints.
Data type numeric
Default value 0.9
Allowed values 0-1
Parameter type dynamic
Documentation checkpoint_completion_target

checkpoint_flush_after

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Number of pages after which previously performed writes are flushed to disk.
Data type integer
Default value 32
Allowed values 32
Parameter type read-only
Documentation checkpoint_flush_after

checkpoint_timeout

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum time between automatic WAL checkpoints, in seconds. The valid range is between 30 seconds and one day.
Data type integer
Default value 600
Allowed values 30-86400
Parameter type dynamic
Documentation checkpoint_timeout

checkpoint_warning

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Writes a warning message if checkpoints caused by the filling of WAL segment more frequently than this.
Data type integer
Default value 30
Allowed values 0-2147483647
Parameter type dynamic
Documentation checkpoint_warning

max_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum size to let the WAL grow before triggering automatic checkpoint.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values 32-65536
Parameter type dynamic
Documentation max_wal_size

Azure-specific notes

The default value for the max_wal_size server parameter is calculated when you provision the instance of Azure Database for PostgreSQL flexible server, based on the product name that you select for its compute. Any subsequent changes of product selection to the compute that supports the flexible server won't have any effect on the default value for the max_wal_size server parameter of that instance.

Every time you change the size of the disk assigned to the instance, you should also adjust the value for the max_wal_size parameter according to the values listed in the following table.

The value is computed based on the size of the disk chosen for the instance, as indicated in the following table:

Disks size max_wal_size
32 GiB 2048 MiB
64 GiB 4096 MiB
128 GiB 12288 MiB
256 GiB 20480 MiB
512 GiB 25600 MiB
512 GiB 25600 MiB
1 TiB 30720 MiB
2 TiB 40960 MiB
4 TiB 40960 MiB
8 TiB 65536 MiB
16 TiB 65536 MiB
32 TiB 65536 MiB

min_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Sets the minimum size to shrink the WAL to.
Data type integer
Default value 80
Allowed values 32-2097151
Parameter type dynamic
Documentation min_wal_size

checkpoint_completion_target

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Specifies the target of checkpoint completion, as a fraction of total time between checkpoints.
Data type numeric
Default value 0.9
Allowed values 0-1
Parameter type dynamic
Documentation checkpoint_completion_target

checkpoint_flush_after

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Number of pages after which previously performed writes are flushed to disk.
Data type integer
Default value 32
Allowed values 32
Parameter type read-only
Documentation checkpoint_flush_after

checkpoint_timeout

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum time between automatic WAL checkpoints, in seconds. The valid range is between 30 seconds and one day.
Data type integer
Default value 600
Allowed values 30-86400
Parameter type dynamic
Documentation checkpoint_timeout

checkpoint_warning

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Writes a warning message if checkpoints caused by the filling of WAL segment more frequently than this.
Data type integer
Default value 30
Allowed values 0-2147483647
Parameter type dynamic
Documentation checkpoint_warning

max_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum size to let the WAL grow before triggering automatic checkpoint.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values 32-65536
Parameter type dynamic
Documentation max_wal_size

Azure-specific notes

The default value for the max_wal_size server parameter is calculated when you provision the instance of Azure Database for PostgreSQL flexible server, based on the product name that you select for its compute. Any subsequent changes of product selection to the compute that supports the flexible server won't have any effect on the default value for the max_wal_size server parameter of that instance.

Every time you change the size of the disk assigned to the instance, you should also adjust the value for the max_wal_size parameter according to the values listed in the following table.

The value is computed based on the size of the disk chosen for the instance, as indicated in the following table:

Disks size max_wal_size
32 GiB 2048 MiB
64 GiB 4096 MiB
128 GiB 12288 MiB
256 GiB 20480 MiB
512 GiB 25600 MiB
512 GiB 25600 MiB
1 TiB 30720 MiB
2 TiB 40960 MiB
4 TiB 40960 MiB
8 TiB 65536 MiB
16 TiB 65536 MiB
32 TiB 65536 MiB

min_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Sets the minimum size to shrink the WAL to.
Data type integer
Default value 80
Allowed values 32-2097151
Parameter type dynamic
Documentation min_wal_size

checkpoint_completion_target

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Specifies the target of checkpoint completion, as a fraction of total time between checkpoints.
Data type numeric
Default value 0.9
Allowed values 0-1
Parameter type dynamic
Documentation checkpoint_completion_target

checkpoint_flush_after

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Number of pages after which previously performed writes are flushed to disk.
Data type integer
Default value 32
Allowed values 32
Parameter type read-only
Documentation checkpoint_flush_after

checkpoint_timeout

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum time between automatic WAL checkpoints, in seconds. The valid range is between 30 seconds and one day.
Data type integer
Default value 600
Allowed values 30-86400
Parameter type dynamic
Documentation checkpoint_timeout

checkpoint_warning

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Writes a warning message if checkpoints caused by the filling of WAL segment more frequently than this.
Data type integer
Default value 30
Allowed values 0-2147483647
Parameter type dynamic
Documentation checkpoint_warning

max_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum size to let the WAL grow before triggering automatic checkpoint.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values 32-65536
Parameter type dynamic
Documentation max_wal_size

Azure-specific notes

The default value for the max_wal_size server parameter is calculated when you provision the instance of Azure Database for PostgreSQL flexible server, based on the product name that you select for its compute. Any subsequent changes of product selection to the compute that supports the flexible server won't have any effect on the default value for the max_wal_size server parameter of that instance.

Every time you change the size of the disk assigned to the instance, you should also adjust the value for the max_wal_size parameter according to the values listed in the following table.

The value is computed based on the size of the disk chosen for the instance, as indicated in the following table:

Disks size max_wal_size
32 GiB 2048 MiB
64 GiB 4096 MiB
128 GiB 12288 MiB
256 GiB 20480 MiB
512 GiB 25600 MiB
512 GiB 25600 MiB
1 TiB 30720 MiB
2 TiB 40960 MiB
4 TiB 40960 MiB
8 TiB 65536 MiB
16 TiB 65536 MiB
32 TiB 65536 MiB

min_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Sets the minimum size to shrink the WAL to.
Data type integer
Default value 80
Allowed values 32-2097151
Parameter type dynamic
Documentation min_wal_size

checkpoint_completion_target

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Specifies the target of checkpoint completion, as a fraction of total time between checkpoints.
Data type numeric
Default value 0.9
Allowed values 0-1
Parameter type dynamic
Documentation checkpoint_completion_target

checkpoint_flush_after

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Number of pages after which previously performed writes are flushed to disk.
Data type integer
Default value 32
Allowed values 32
Parameter type read-only
Documentation checkpoint_flush_after

checkpoint_timeout

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum time between automatic WAL checkpoints, in seconds. The valid range is between 30 seconds and one day.
Data type integer
Default value 600
Allowed values 30-86400
Parameter type dynamic
Documentation checkpoint_timeout

checkpoint_warning

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Writes a warning message if checkpoints caused by the filling of WAL segment more frequently than this.
Data type integer
Default value 30
Allowed values 0-2147483647
Parameter type dynamic
Documentation checkpoint_warning

max_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum size to let the WAL grow before triggering automatic checkpoint.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values 32-65536
Parameter type dynamic
Documentation max_wal_size

Azure-specific notes

The default value for the max_wal_size server parameter is calculated when you provision the instance of Azure Database for PostgreSQL flexible server, based on the product name that you select for its compute. Any subsequent changes of product selection to the compute that supports the flexible server won't have any effect on the default value for the max_wal_size server parameter of that instance.

Every time you change the size of the disk assigned to the instance, you should also adjust the value for the max_wal_size parameter according to the values listed in the following table.

The value is computed based on the size of the disk chosen for the instance, as indicated in the following table:

Disks size max_wal_size
32 GiB 2048 MiB
64 GiB 4096 MiB
128 GiB 12288 MiB
256 GiB 20480 MiB
512 GiB 25600 MiB
512 GiB 25600 MiB
1 TiB 30720 MiB
2 TiB 40960 MiB
4 TiB 40960 MiB
8 TiB 65536 MiB
16 TiB 65536 MiB
32 TiB 65536 MiB

min_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Sets the minimum size to shrink the WAL to.
Data type integer
Default value 80
Allowed values 32-2097151
Parameter type dynamic
Documentation min_wal_size

checkpoint_completion_target

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Specifies the target of checkpoint completion, as a fraction of total time between checkpoints.
Data type numeric
Default value 0.9
Allowed values 0-1
Parameter type dynamic
Documentation checkpoint_completion_target

checkpoint_flush_after

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Number of pages after which previously performed writes are flushed to disk.
Data type integer
Default value 32
Allowed values 32
Parameter type read-only
Documentation checkpoint_flush_after

checkpoint_timeout

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum time between automatic WAL checkpoints, in seconds. The valid range is between 30 seconds and one day.
Data type integer
Default value 600
Allowed values 30-86400
Parameter type dynamic
Documentation checkpoint_timeout

checkpoint_warning

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Writes a warning message if checkpoints caused by the filling of WAL segment more frequently than this.
Data type integer
Default value 30
Allowed values 0-2147483647
Parameter type dynamic
Documentation checkpoint_warning

max_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Maximum size to let the WAL grow before triggering automatic checkpoint.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values 32-65536
Parameter type dynamic
Documentation max_wal_size

Azure-specific notes

The default value for the max_wal_size server parameter is calculated when you provision the instance of Azure Database for PostgreSQL flexible server, based on the product name that you select for its compute. Any subsequent changes of product selection to the compute that supports the flexible server won't have any effect on the default value for the max_wal_size server parameter of that instance.

Every time you change the size of the disk assigned to the instance, you should also adjust the value for the max_wal_size parameter according to the values listed in the following table.

The value is computed based on the size of the disk chosen for the instance, as indicated in the following table:

Disks size max_wal_size
32 GiB 2048 MiB
64 GiB 4096 MiB
128 GiB 12288 MiB
256 GiB 20480 MiB
512 GiB 25600 MiB
512 GiB 25600 MiB
1 TiB 30720 MiB
2 TiB 40960 MiB
4 TiB 40960 MiB
8 TiB 65536 MiB
16 TiB 65536 MiB
32 TiB 65536 MiB

min_wal_size

Attribute Value
Category Write-Ahead Log / Checkpoints
Description Sets the minimum size to shrink the WAL to.
Data type integer
Default value 80
Allowed values 32-2097151
Parameter type dynamic
Documentation min_wal_size