Purpose
The RECONFIG command starts the reconfiguration process, which changes the Teradata Database system configuration. Prior to performing a reconfiguration, a new configuration map must have been defined using the Configuration utility.
The command can also be used to change certain reconfiguration parameters after the process has begun.
Syntax
- DISPLAY
- whether to enable or disable output of Reconfiguration status (but not statistics):
- n TASKS
- the limitation of the number of Reconfiguration sessions running in parallel.
- [CPU | IO] PRIORITY p
- the job settings to use for the reconfiguration. The default is to assign the reconfiguration process a medium timeshare access level.
- PAUSE
- whether Reconfiguration is to pause before entering the auto-restart phase.
- STATISTICS
- whether to enable or disable output of Reconfiguration statistics:
Usage Notes
The RECONFIG command can be used throughout the reconfiguration process to change the values of TASK, PRIORITY, JOURNAL MAXPERMSPACE, and STATISTICS.
| Prompt | Explanation |
|---|---|
AMPs are added into configuration, do you want all new space to go to user DBC? (yes or no) (If you choose no, added space is divided among the impacted databases and users in proportion to their current space allocations.) |
When new AMPs are added to the system, this prompt lets you choose whether
the new space is given exclusively to DBC, or divided proportionately among impacted databases and
users. As an example of dividing the new space proportionately among existing databases and users, if existing database db1 has a max perm space of x, and database db2 has a max perm space of 2x, when the space is expanded db1 would get additional space of y, and db2 would get additional space of 2y. |
Which map should be the system-default map. (map name or number)? |
The system default map is the contiguous map used for tables and join indexes subsequently created if no map is explicitly specified in the CREATE statement, and if the table creator has no other default map assigned. For more information on default map precedence, see SQL Data Definition Language - Syntax and Examples. When Reconfig starts, it displays the contiguous maps on the system with their corresponding map numbers. Map numbers 1 and 2 are reserved for Data Dictionary (DBC) tables, and cannot be specified as the system default map. |
Reconfig will update the system-default map to newmap (Map Number nnnn). Reconfig will make the new map available. Which tables should reconfig process? 1. No tables 2. Dictionary tables 3. User tables with contiguous maps specified in DBC.ReconfigRedistOrderTbl 4. All user tables with contiguous maps. |
This prompt verifies the system default map and allows you to choose which
tables should be processed by the Reconfiguration utility. To shorten the time that the Reconfig utility keeps the system down and unavailable, you can choose No Tables, and, after the reconfiguration is complete, use the ALTER TABLE MAP statement to set existing user tables to use the new contiguous map. In this way their rows are redistributed in the background while the database is running and available. Alternatively, you can use the Advisor and Mover tool procedures to help automate this process. For more information about ALTER TABLE MAP, see SQL Data Definition Language - Syntax and Examples. For more information about the Advisor and Mover tools, see Database Administration. Data Dictionary tables, if specified to be moved during the reconfiguration, must be moved by the Reconfiguration utility itself. |
Example: Running RECONFIG suppressing statistics output
To disable statistics output, type:
reconfig with statistics off
Example: Running RECONFIG with 10 parallel sessions
To reconfigure with 10 control tasks and statistics output disabled, type:
reconfig with 10 tasks statistics off
Example: Running RECONFIG suppressing all display output
To reconfigure with eight control tasks and output display disabled, type:
reconfig with 8 tasks display off
Example: Typical RECONFIG output
This example shows some output from the RECONFIG command. Reconfiguration output displays the following:
- Start and end time of each table processed during redistribution
- Run-time statistics of the table process that includes statistics for all AMPs
This information is included with the deletion and NUSI building. The output might become excessive for a large number of tables, so you might want to disable DISPLAY. If you disable DISPLAY, you can still obtain status using the STATUS command.
You can disable the table begin/completion output with the RECONFIG WITH DISPLAY OFF command. You can disable the statistics output with the RECONFIG WITH STATISTICS OFF command.
08/05/13 09:04:35 Task 01 Begin redistribution DBC.Global (0000H 0019H). 08/05/13 09:04:35 Task 00 Begin redistribution DBC.TransientJournal (0000H 001AH). 08/05/13 09:04:35 Task 00 End redistribution DBC.TransientJournal (0000H 001AH). Statistics: RowCount ByteCount TotSecs CPUSecs IOCount AllAmps: 0 0 0 0 0 08/05/13 09:04:36 Task 02 Begin redistribution DBC.Owners (0000H 001BH). 08/05/13 09:04:36 Task 01 End redistribution DBC.Global (0000H 0019H). Statistics: RowCount ByteCount TotSecs CPUSecs IOCount AllAmps: 2 0 0 0 2,564 08/05/13 09:04:36 Task 00 Begin redistribution DBC.Parents (0000H 001CH). 08/05/13 09:04:36 Task 02 End redistribution DBC.Owners (0000H 001BH). Statistics: RowCount ByteCount TotSecs CPUSecs IOCount AllAmps: 18 0 0 0 2,831 08/05/13 09:04:36 Task 00 End redistribution DBC.Parents (0000H 001CH). Statistics: RowCount ByteCount TotSecs CPUSecs IOCount AllAmps: 13 0 0 0 2,943 08/05/13 09:04:36 Task 01 Begin redistribution DBC.ErrorMsgs (0000H 001EH). 08/05/13 09:04:36 Task 00 Begin redistribution DBC.ChangedRowJournal (0000H 0020H). 08/05/13 09:04:36 Task 00 End redistribution DBC.ChangedRowJournal (0000H 0020H). Statistics: RowCount ByteCount TotSecs CPUSecs IOCount AllAmps: 0 0 0 0 0