Alter WAL

Alters table write-ahead log (WAL) settings. Returns information about the requested table WAL modifications.

Input Parameter Description

NameTypeDescription
table_namesarray of stringsList of tables to modify. An asterisk changes the system settings.
optionsmap of string to strings

Optional parameters. The default value is an empty map ( {} ).

Supported Parameters (keys)Parameter Description
max_segment_sizeMaximum size of an individual segment file
segment_countApproximate number of segment files to split the WAL across. Must be at least two.
sync_policy

Maximum size of an individual segment file

Supported ValuesDescription
noneDisables the WAL
backgroundWAL entries are periodically written instead of immediately after each operation
flushProtects entries in the event of a database crash
fsyncProtects entries in the event of an OS crash
flush_frequencySpecifies how frequently WAL entries are written with background sync. This is a global setting and can only be used with the system {options.table_names} specifier '*'.
checksum

If true each entry will be checked against a protective checksum. The default value is true. The supported values are:

  • true
  • false
override_non_default

If true tables with unique WAL settings will be overridden when applying a system level change. The default value is false. The supported values are:

  • true
  • false
restore_system_settings

If true tables with unique WAL settings will be reverted to the current global settings. Cannot be used in conjunction with any other option. The default value is false. The supported values are:

  • true
  • false
persist

If true and a system-level change was requested, the system configuration will be written to disk upon successful application of this request. This will commit the changes from this request and any additional in-memory modifications. The default value is true. The supported values are:

  • true
  • false

Output Parameter Description

NameTypeDescription
infomap of string to stringsAdditional information.