Write-Ahead Log / Settings

commit_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the delay in microseconds between transaction commit and flushing WAL to disk.
Data type integer
Default value 0
Allowed values 0-100000
Parameter type dynamic
Documentation commit_delay

commit_siblings

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the minimum concurrent open transactions before performing commit_delay.
Data type integer
Default value 5
Allowed values 0-1000
Parameter type dynamic
Documentation commit_siblings

fsync

Attribute Value
Category Write-Ahead Log / Settings
Description Forces synchronization of updates to disk.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation fsync

full_page_writes

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation full_page_writes

synchronous_commit

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the current transaction's synchronization level.
Data type enumeration
Default value on
Allowed values on
Parameter type read-only
Documentation synchronous_commit

wal_buffers

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the number of disk-page buffers in shared memory for WAL. Unit is 8kb.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values -1-262143
Parameter type static
Documentation wal_buffers

Azure-specific notes

The default value for the wal_buffers 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 wal_buffers server parameter of that instance.

Every time you change the product assigned to an instance, you should also adjust the value for the wal_buffers parameter according to the values in the following formula.

In virtual machines with up to 4 vCores, the value computed for wal_buffers is 2048.

In virtual machines with more than 4 vCores, the value computed for wal_buffers is 16384.

Based on the previous formula, the following table lists the values this server parameter would be set to depending on the amount of memory provisioned:

vCores wal_buffers
1 2048
2 2048
4 2048
8 16384
12 16384
16 16384
20 16384
32 16384
48 16384
64 16384
96 16384

wal_compression

Attribute Value
Category Write-Ahead Log / Settings
Description Compresses full-page writes written in WAL file.
Data type boolean
Default value on
Allowed values on,off
Parameter type dynamic
Documentation wal_compression

wal_init_zero

Attribute Value
Category Write-Ahead Log / Settings
Description Writes zeroes to new WAL files before first use.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_init_zero

wal_level

Attribute Value
Category Write-Ahead Log / Settings
Description It determines how much information is written to the WAL.
Data type enumeration
Default value replica
Allowed values replica,logical
Parameter type static
Documentation wal_level

wal_log_hints

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modification.
Data type boolean
Default value off
Allowed values off
Parameter type read-only
Documentation wal_log_hints

wal_recycle

Attribute Value
Category Write-Ahead Log / Settings
Description Recycles WAL files by renaming them.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_recycle

wal_skip_threshold

Attribute Value
Category Write-Ahead Log / Settings
Description Minimum size of new file to fsync instead of writing WAL.
Data type integer
Default value 2048
Allowed values 2048
Parameter type read-only
Documentation wal_skip_threshold

wal_sync_method

Attribute Value
Category Write-Ahead Log / Settings
Description Selects the method used for forcing WAL updates to disk.
Data type enumeration
Default value fdatasync
Allowed values fdatasync
Parameter type read-only
Documentation wal_sync_method

wal_writer_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Time interval between WAL flushes performed by the WAL writer.
Data type integer
Default value 200
Allowed values 1-10000
Parameter type dynamic
Documentation wal_writer_delay

wal_writer_flush_after

Attribute Value
Category Write-Ahead Log / Settings
Description Amount of WAL written out by WAL writer that triggers a flush.
Data type integer
Default value 128
Allowed values 0-2147483647
Parameter type dynamic
Documentation wal_writer_flush_after

commit_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the delay in microseconds between transaction commit and flushing WAL to disk.
Data type integer
Default value 0
Allowed values 0-100000
Parameter type dynamic
Documentation commit_delay

commit_siblings

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the minimum concurrent open transactions before performing commit_delay.
Data type integer
Default value 5
Allowed values 0-1000
Parameter type dynamic
Documentation commit_siblings

fsync

Attribute Value
Category Write-Ahead Log / Settings
Description Forces synchronization of updates to disk.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation fsync

full_page_writes

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation full_page_writes

synchronous_commit

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the current transaction's synchronization level.
Data type enumeration
Default value on
Allowed values on
Parameter type read-only
Documentation synchronous_commit

wal_buffers

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the number of disk-page buffers in shared memory for WAL. Unit is 8kb.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values -1-262143
Parameter type static
Documentation wal_buffers

Azure-specific notes

The default value for the wal_buffers 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 wal_buffers server parameter of that instance.

Every time you change the product assigned to an instance, you should also adjust the value for the wal_buffers parameter according to the values in the following formula.

In virtual machines with up to 4 vCores, the value computed for wal_buffers is 2048.

In virtual machines with more than 4 vCores, the value computed for wal_buffers is 16384.

Based on the previous formula, the following table lists the values this server parameter would be set to depending on the amount of memory provisioned:

vCores wal_buffers
1 2048
2 2048
4 2048
8 16384
12 16384
16 16384
20 16384
32 16384
48 16384
64 16384
96 16384

wal_compression

Attribute Value
Category Write-Ahead Log / Settings
Description Compresses full-page writes written in WAL file.
Data type boolean
Default value on
Allowed values on,off
Parameter type dynamic
Documentation wal_compression

wal_init_zero

Attribute Value
Category Write-Ahead Log / Settings
Description Writes zeroes to new WAL files before first use.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_init_zero

wal_level

Attribute Value
Category Write-Ahead Log / Settings
Description It determines how much information is written to the WAL.
Data type enumeration
Default value replica
Allowed values replica,logical
Parameter type static
Documentation wal_level

wal_log_hints

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modification.
Data type boolean
Default value off
Allowed values off
Parameter type read-only
Documentation wal_log_hints

wal_recycle

Attribute Value
Category Write-Ahead Log / Settings
Description Recycles WAL files by renaming them.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_recycle

wal_skip_threshold

Attribute Value
Category Write-Ahead Log / Settings
Description Minimum size of new file to fsync instead of writing WAL.
Data type integer
Default value 2048
Allowed values 2048
Parameter type read-only
Documentation wal_skip_threshold

wal_sync_method

Attribute Value
Category Write-Ahead Log / Settings
Description Selects the method used for forcing WAL updates to disk.
Data type enumeration
Default value fdatasync
Allowed values fdatasync
Parameter type read-only
Documentation wal_sync_method

wal_writer_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Time interval between WAL flushes performed by the WAL writer.
Data type integer
Default value 200
Allowed values 1-10000
Parameter type dynamic
Documentation wal_writer_delay

wal_writer_flush_after

Attribute Value
Category Write-Ahead Log / Settings
Description Amount of WAL written out by WAL writer that triggers a flush.
Data type integer
Default value 128
Allowed values 0-2147483647
Parameter type dynamic
Documentation wal_writer_flush_after

commit_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the delay in microseconds between transaction commit and flushing WAL to disk.
Data type integer
Default value 0
Allowed values 0-100000
Parameter type dynamic
Documentation commit_delay

commit_siblings

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the minimum concurrent open transactions before performing commit_delay.
Data type integer
Default value 5
Allowed values 0-1000
Parameter type dynamic
Documentation commit_siblings

fsync

Attribute Value
Category Write-Ahead Log / Settings
Description Forces synchronization of updates to disk.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation fsync

full_page_writes

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation full_page_writes

synchronous_commit

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the current transaction's synchronization level.
Data type enumeration
Default value on
Allowed values on
Parameter type read-only
Documentation synchronous_commit

wal_buffers

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the number of disk-page buffers in shared memory for WAL. Unit is 8kb.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values -1-262143
Parameter type static
Documentation wal_buffers

Azure-specific notes

The default value for the wal_buffers 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 wal_buffers server parameter of that instance.

Every time you change the product assigned to an instance, you should also adjust the value for the wal_buffers parameter according to the values in the following formula.

In virtual machines with up to 4 vCores, the value computed for wal_buffers is 2048.

In virtual machines with more than 4 vCores, the value computed for wal_buffers is 16384.

Based on the previous formula, the following table lists the values this server parameter would be set to depending on the amount of memory provisioned:

vCores wal_buffers
1 2048
2 2048
4 2048
8 16384
12 16384
16 16384
20 16384
32 16384
48 16384
64 16384
96 16384

wal_compression

Attribute Value
Category Write-Ahead Log / Settings
Description Compresses full-page writes written in WAL file.
Data type boolean
Default value on
Allowed values on,off
Parameter type dynamic
Documentation wal_compression

wal_init_zero

Attribute Value
Category Write-Ahead Log / Settings
Description Writes zeroes to new WAL files before first use.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_init_zero

wal_level

Attribute Value
Category Write-Ahead Log / Settings
Description It determines how much information is written to the WAL.
Data type enumeration
Default value replica
Allowed values replica,logical
Parameter type static
Documentation wal_level

wal_log_hints

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modification.
Data type boolean
Default value off
Allowed values off
Parameter type read-only
Documentation wal_log_hints

wal_recycle

Attribute Value
Category Write-Ahead Log / Settings
Description Recycles WAL files by renaming them.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_recycle

wal_skip_threshold

Attribute Value
Category Write-Ahead Log / Settings
Description Minimum size of new file to fsync instead of writing WAL.
Data type integer
Default value 2048
Allowed values 2048
Parameter type read-only
Documentation wal_skip_threshold

wal_sync_method

Attribute Value
Category Write-Ahead Log / Settings
Description Selects the method used for forcing WAL updates to disk.
Data type enumeration
Default value fdatasync
Allowed values fdatasync
Parameter type read-only
Documentation wal_sync_method

wal_writer_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Time interval between WAL flushes performed by the WAL writer.
Data type integer
Default value 200
Allowed values 1-10000
Parameter type dynamic
Documentation wal_writer_delay

wal_writer_flush_after

Attribute Value
Category Write-Ahead Log / Settings
Description Amount of WAL written out by WAL writer that triggers a flush.
Data type integer
Default value 128
Allowed values 0-2147483647
Parameter type dynamic
Documentation wal_writer_flush_after

commit_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the delay in microseconds between transaction commit and flushing WAL to disk.
Data type integer
Default value 0
Allowed values 0-100000
Parameter type dynamic
Documentation commit_delay

commit_siblings

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the minimum concurrent open transactions before performing commit_delay.
Data type integer
Default value 5
Allowed values 0-1000
Parameter type dynamic
Documentation commit_siblings

fsync

Attribute Value
Category Write-Ahead Log / Settings
Description Forces synchronization of updates to disk.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation fsync

full_page_writes

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation full_page_writes

synchronous_commit

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the current transaction's synchronization level.
Data type enumeration
Default value on
Allowed values on
Parameter type read-only
Documentation synchronous_commit

wal_buffers

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the number of disk-page buffers in shared memory for WAL. Unit is 8kb.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values -1-262143
Parameter type static
Documentation wal_buffers

Azure-specific notes

The default value for the wal_buffers 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 wal_buffers server parameter of that instance.

Every time you change the product assigned to an instance, you should also adjust the value for the wal_buffers parameter according to the values in the following formula.

In virtual machines with up to 4 vCores, the value computed for wal_buffers is 2048.

In virtual machines with more than 4 vCores, the value computed for wal_buffers is 16384.

Based on the previous formula, the following table lists the values this server parameter would be set to depending on the amount of memory provisioned:

vCores wal_buffers
1 2048
2 2048
4 2048
8 16384
12 16384
16 16384
20 16384
32 16384
48 16384
64 16384
96 16384

wal_compression

Attribute Value
Category Write-Ahead Log / Settings
Description Compresses full-page writes written in WAL file.
Data type boolean
Default value on
Allowed values on,off
Parameter type dynamic
Documentation wal_compression

wal_init_zero

Attribute Value
Category Write-Ahead Log / Settings
Description Writes zeroes to new WAL files before first use.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_init_zero

wal_level

Attribute Value
Category Write-Ahead Log / Settings
Description It determines how much information is written to the WAL.
Data type enumeration
Default value replica
Allowed values replica,logical
Parameter type static
Documentation wal_level

wal_log_hints

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modification.
Data type boolean
Default value off
Allowed values off
Parameter type read-only
Documentation wal_log_hints

wal_recycle

Attribute Value
Category Write-Ahead Log / Settings
Description Recycles WAL files by renaming them.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_recycle

wal_skip_threshold

Attribute Value
Category Write-Ahead Log / Settings
Description Minimum size of new file to fsync instead of writing WAL.
Data type integer
Default value 2048
Allowed values 2048
Parameter type read-only
Documentation wal_skip_threshold

wal_sync_method

Attribute Value
Category Write-Ahead Log / Settings
Description Selects the method used for forcing WAL updates to disk.
Data type enumeration
Default value fdatasync
Allowed values fdatasync
Parameter type read-only
Documentation wal_sync_method

wal_writer_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Time interval between WAL flushes performed by the WAL writer.
Data type integer
Default value 200
Allowed values 1-10000
Parameter type dynamic
Documentation wal_writer_delay

wal_writer_flush_after

Attribute Value
Category Write-Ahead Log / Settings
Description Amount of WAL written out by WAL writer that triggers a flush.
Data type integer
Default value 128
Allowed values 0-2147483647
Parameter type dynamic
Documentation wal_writer_flush_after

commit_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the delay in microseconds between transaction commit and flushing WAL to disk.
Data type integer
Default value 0
Allowed values 0-100000
Parameter type dynamic
Documentation commit_delay

commit_siblings

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the minimum concurrent open transactions before performing commit_delay.
Data type integer
Default value 5
Allowed values 0-1000
Parameter type dynamic
Documentation commit_siblings

fsync

Attribute Value
Category Write-Ahead Log / Settings
Description Forces synchronization of updates to disk.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation fsync

full_page_writes

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation full_page_writes

synchronous_commit

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the current transaction's synchronization level.
Data type enumeration
Default value on
Allowed values on
Parameter type read-only
Documentation synchronous_commit

wal_buffers

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the number of disk-page buffers in shared memory for WAL. Unit is 8kb.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values -1-262143
Parameter type static
Documentation wal_buffers

Azure-specific notes

The default value for the wal_buffers 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 wal_buffers server parameter of that instance.

Every time you change the product assigned to an instance, you should also adjust the value for the wal_buffers parameter according to the values in the following formula.

In virtual machines with up to 4 vCores, the value computed for wal_buffers is 2048.

In virtual machines with more than 4 vCores, the value computed for wal_buffers is 16384.

Based on the previous formula, the following table lists the values this server parameter would be set to depending on the amount of memory provisioned:

vCores wal_buffers
1 2048
2 2048
4 2048
8 16384
12 16384
16 16384
20 16384
32 16384
48 16384
64 16384
96 16384

wal_compression

Attribute Value
Category Write-Ahead Log / Settings
Description Compresses full-page writes written in WAL file.
Data type boolean
Default value on
Allowed values on,off
Parameter type dynamic
Documentation wal_compression

wal_init_zero

Attribute Value
Category Write-Ahead Log / Settings
Description Writes zeroes to new WAL files before first use.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_init_zero

wal_level

Attribute Value
Category Write-Ahead Log / Settings
Description It determines how much information is written to the WAL.
Data type enumeration
Default value replica
Allowed values replica,logical
Parameter type static
Documentation wal_level

wal_log_hints

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modification.
Data type boolean
Default value off
Allowed values off
Parameter type read-only
Documentation wal_log_hints

wal_recycle

Attribute Value
Category Write-Ahead Log / Settings
Description Recycles WAL files by renaming them.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_recycle

wal_skip_threshold

Attribute Value
Category Write-Ahead Log / Settings
Description Size of new file to fsync instead of writing WAL.
Data type integer
Default value 2048
Allowed values 2048
Parameter type read-only
Documentation wal_skip_threshold

wal_sync_method

Attribute Value
Category Write-Ahead Log / Settings
Description Selects the method used for forcing WAL updates to disk.
Data type enumeration
Default value fdatasync
Allowed values fdatasync
Parameter type read-only
Documentation wal_sync_method

wal_writer_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Time interval between WAL flushes performed by the WAL writer.
Data type integer
Default value 200
Allowed values 1-10000
Parameter type dynamic
Documentation wal_writer_delay

wal_writer_flush_after

Attribute Value
Category Write-Ahead Log / Settings
Description Amount of WAL written out by WAL writer that triggers a flush.
Data type integer
Default value 128
Allowed values 0-2147483647
Parameter type dynamic
Documentation wal_writer_flush_after

commit_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the delay in microseconds between transaction commit and flushing WAL to disk.
Data type integer
Default value 0
Allowed values 0-100000
Parameter type dynamic
Documentation commit_delay

commit_siblings

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the minimum concurrent open transactions before performing commit_delay.
Data type integer
Default value 5
Allowed values 0-1000
Parameter type dynamic
Documentation commit_siblings

fsync

Attribute Value
Category Write-Ahead Log / Settings
Description Forces synchronization of updates to disk.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation fsync

full_page_writes

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation full_page_writes

synchronous_commit

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the current transaction's synchronization level.
Data type enumeration
Default value on
Allowed values on
Parameter type read-only
Documentation synchronous_commit

wal_buffers

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the number of disk-page buffers in shared memory for WAL. Unit is 8kb.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values -1-262143
Parameter type static
Documentation wal_buffers

Azure-specific notes

The default value for the wal_buffers 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 wal_buffers server parameter of that instance.

Every time you change the product assigned to an instance, you should also adjust the value for the wal_buffers parameter according to the values in the following formula.

In virtual machines with up to 4 vCores, the value computed for wal_buffers is 2048.

In virtual machines with more than 4 vCores, the value computed for wal_buffers is 16384.

Based on the previous formula, the following table lists the values this server parameter would be set to depending on the amount of memory provisioned:

vCores wal_buffers
1 2048
2 2048
4 2048
8 16384
12 16384
16 16384
20 16384
32 16384
48 16384
64 16384
96 16384

wal_compression

Attribute Value
Category Write-Ahead Log / Settings
Description Compresses full-page writes written in WAL file.
Data type boolean
Default value on
Allowed values on,off
Parameter type dynamic
Documentation wal_compression

wal_init_zero

Attribute Value
Category Write-Ahead Log / Settings
Description Writes zeroes to new WAL files before first use.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_init_zero

wal_level

Attribute Value
Category Write-Ahead Log / Settings
Description It determines how much information is written to the WAL.
Data type enumeration
Default value replica
Allowed values replica,logical
Parameter type static
Documentation wal_level

wal_log_hints

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modification.
Data type boolean
Default value off
Allowed values off
Parameter type read-only
Documentation wal_log_hints

wal_recycle

Attribute Value
Category Write-Ahead Log / Settings
Description Recycles WAL files by renaming them.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation wal_recycle

wal_sync_method

Attribute Value
Category Write-Ahead Log / Settings
Description Selects the method used for forcing WAL updates to disk.
Data type enumeration
Default value fdatasync
Allowed values fdatasync
Parameter type read-only
Documentation wal_sync_method

wal_writer_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Time interval between WAL flushes performed by the WAL writer.
Data type integer
Default value 200
Allowed values 1-10000
Parameter type dynamic
Documentation wal_writer_delay

wal_writer_flush_after

Attribute Value
Category Write-Ahead Log / Settings
Description Amount of WAL written out by WAL writer that triggers a flush.
Data type integer
Default value 128
Allowed values 0-2147483647
Parameter type dynamic
Documentation wal_writer_flush_after

commit_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the delay in microseconds between transaction commit and flushing WAL to disk.
Data type integer
Default value 0
Allowed values 0-100000
Parameter type dynamic
Documentation commit_delay

commit_siblings

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the minimum concurrent open transactions before performing commit_delay.
Data type integer
Default value 5
Allowed values 0-1000
Parameter type dynamic
Documentation commit_siblings

fsync

Attribute Value
Category Write-Ahead Log / Settings
Description Forces synchronization of updates to disk.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation fsync

full_page_writes

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint.
Data type boolean
Default value on
Allowed values on
Parameter type read-only
Documentation full_page_writes

synchronous_commit

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the current transaction's synchronization level.
Data type enumeration
Default value on
Allowed values on
Parameter type read-only
Documentation synchronous_commit

wal_buffers

Attribute Value
Category Write-Ahead Log / Settings
Description Sets the number of disk-page buffers in shared memory for WAL. Unit is 8kb.
Data type integer
Default value Depends on resources (vCores, RAM, or disk space) allocated to the server.
Allowed values -1-262143
Parameter type static
Documentation wal_buffers

Azure-specific notes

The default value for the wal_buffers 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 wal_buffers server parameter of that instance.

Every time you change the product assigned to an instance, you should also adjust the value for the wal_buffers parameter according to the values in the following formula.

In virtual machines with up to 4 vCores, the value computed for wal_buffers is 2048.

In virtual machines with more than 4 vCores, the value computed for wal_buffers is 16384.

Based on the previous formula, the following table lists the values this server parameter would be set to depending on the amount of memory provisioned:

vCores wal_buffers
1 2048
2 2048
4 2048
8 16384
12 16384
16 16384
20 16384
32 16384
48 16384
64 16384
96 16384

wal_compression

Attribute Value
Category Write-Ahead Log / Settings
Description Compresses full-page writes written in WAL file.
Data type boolean
Default value on
Allowed values on,off
Parameter type dynamic
Documentation wal_compression

wal_level

Attribute Value
Category Write-Ahead Log / Settings
Description It determines how much information is written to the WAL.
Data type enumeration
Default value replica
Allowed values replica,logical
Parameter type static
Documentation wal_level

wal_log_hints

Attribute Value
Category Write-Ahead Log / Settings
Description Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modification.
Data type boolean
Default value off
Allowed values off
Parameter type read-only
Documentation wal_log_hints

wal_sync_method

Attribute Value
Category Write-Ahead Log / Settings
Description Selects the method used for forcing WAL updates to disk.
Data type enumeration
Default value fdatasync
Allowed values fdatasync
Parameter type read-only
Documentation wal_sync_method

wal_writer_delay

Attribute Value
Category Write-Ahead Log / Settings
Description Time interval between WAL flushes performed by the WAL writer.
Data type integer
Default value 200
Allowed values 1-10000
Parameter type dynamic
Documentation wal_writer_delay

wal_writer_flush_after

Attribute Value
Category Write-Ahead Log / Settings
Description Amount of WAL written out by WAL writer that triggers a flush.
Data type integer
Default value 128
Allowed values 0-2147483647
Parameter type dynamic
Documentation wal_writer_flush_after