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    alterWal

    public AlterWalResponse alterWal(AlterWalRequest request) throws GPUdbException
    Alters table write-ahead log (WAL) settings. Returns information about the requested table WAL modifications.
    Parameters:
    request - Request object containing the parameters for the operation.
    Returns:
    Response object containing the results of the operation.
    Throws:
    GPUdbException - if an error occurs during the operation.

  • ​
    alterWal

    public AlterWalResponse alterWal(List<String> tableNames, Map<String,String> options) throws GPUdbException
    Alters table write-ahead log (WAL) settings. Returns information about the requested table WAL modifications.
    Parameters:
    tableNames - List of tables to modify. An asterisk changes the system settings.
    options - Optional parameters.
    • 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:
      • 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. Supported values:The default value is TRUE.
    • OVERRIDE_NON_DEFAULT: If TRUE tables with unique WAL settings will be overridden when applying a system level change. Supported values:The default value is 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. Supported values:The default value is 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. Supported values:The default value is TRUE.
    The default value is an empty Map.
    Returns:
    Response object containing the results of the operation.
    Throws:
    GPUdbException - if an error occurs during the operation.