alterdb Command--Set Database Characteristics
Permission required: DBA or a privileged user running as the DBA.
The alterdb command sets journaling and other characteristics for a database. You can use alterdb to halt journaling for a specified database. To restart journaling, you must use the ckpdb +j command.
The alterdb command has the following format:
alterdb [-disable_journaling] [-delete_oldest_ckp]
[-init_jnl_blocks=n] [-jnl_block_size=n] [-next_jnl_file]
[-target_jnl_blocks=n] [-delete_invalid_ckp] [-n|-i[ucollation_name]]
[-keep=n] [-disable_mvcc] [-enable_mvcc]
[-enable_mustlog] [-disable_mustlog]
[‑readonly|‑readwrite] [-verbose] [-help]
dbname[/server_class]
-disable_journaling
Halts journaling immediately, regardless of whether users are connected to the database.
Note: A side effect of using alterdb to disable journaling is that incorrect journaling status is displayed for tables. Tables display journaling as enabled although journaling is disabled for the database where you would expect enabled after next checkpoint.
-delete_oldest_ckp
Deletes the oldest available checkpoint, including related journals and dump files. The request fails if you attempt to delete the only remaining valid checkpoint.
-init_jnl_blocks=n
Specifies the size of the first journal file created after a checkpoint is taken (with the ckpdb command), where 0 <= n <= current target journal size.
The target journal size is displayed by infodb and is the parameter set by the -target_jnl_blocks flag.
-jnl_block_size=n
Specifies the size of each journal file block for the database, where n = 4096, 8192, 16384, 32768, or 65536 bytes. The current size can be obtained by the infodb Journal block size parameter.
Journaling must be off when issuing this command.
-next_jnl_file
Starts a new journal file for this database.
-target_jnl_blocks=n
Specifies the number of journal blocks to be used for the database’s journal file, where 32 <= n <= 65536. The current size can be obtained by the infodb Target journal size parameter.
If using Ingres Cluster Solution, this option has no effect on journal files created as part of a cluster merge.
-delete_invalid_ckp
Deletes all invalid checkpoints. Where there is a previous valid checkpoint, the journal and dump files associated with the invalid checkpoint are retained. For invalid checkpoints with no previous valid checkpoint, associated journal and dump files are removed.
-n[ucollation_name]
Converts a non-Unicode database to a Unicode database with Normalization Form D (NFD). If no collation name is specified, the default collation (udefault) is used.
-i[ucollation_name]
Converts a non-Unicode database to a Unicode database with Normalization Form C (NFC). If no collation name is specified, the default collation (udefault) is used.
-keep=n
Preserves the specified number of last valid checkpoints and deletes all older checkpoints, valid or invalid.
-disable_mvcc
Rejects requests for MVCC lock levels the next time the database is opened.
-enable_mvcc
Accepts requests for MVCC lock levels the next time the database is opened.
-enable_mustlog
Indicates that all operations on this database must be logged. Attempts to use SET NOLOGGING on this database will be rejected.
-disable_mustlog
Disables the directive to log all operations on this database.
-readonly|-readwrite
Sets a read-write database to read-only, or sets a read-only database to read-write.
-verbose
Displays system commentary to the standard output device as the alterdb operation continues. This parameter can be used with any one other alterdb parameter.
-help
Displays command syntax online.
dbname
Specifies the database name. Specify one database name only.
Last modified date: 12/06/2024