/alter/wal

URL: http://<db.host>:<db.port>/alter/wal

Alters table wal settings. Returns information about the requested table wal modifications.

Input Parameter Description

Name

Type

Description

table_names

array of strings

List of tables to modify. An asterisk changes the system settings.

options

map of string to strings

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

Supported Parameters (keys)

Parameter Description

max_segment_size

Maximum size of an individual segment file

segment_count

Approximate number of segment files to split the wal across. Must be at least two.

sync_policy

Maximum size of an individual segment file

Supported Values	Description
none	Disables the wal
background	Wal entries are periodically written instead of immediately after each operation
flush	Protects entries in the event of a database crash
fsync	Protects entries in the event of an OS crash

flush_frequency

Specifies 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

The GPUdb server embeds the endpoint response inside a standard response structure which contains status information and the actual response to the query. Here is a description of the various fields of the wrapper:

Name

Type

Description

status

String

'OK' or 'ERROR'

message

String

Empty if success or an error message

data_type

String

'alter_wal_response' or 'none' in case of an error

data

String

Empty string

data_str

JSON or String

This embedded JSON represents the result of the /alter/wal endpoint:

Name	Type	Description
info	map of string to strings	Additional information.

Empty string in case of an error.