The following settings and configurations maybe optimized in high volume transactions to achieve higher performance.
| Variable | Description |
|---|---|
| STATUS_BEAT_LCR | This determines how often a log message is written showing number of processed LCRs (in LCR count) (use 0 to disable). As of Dbvisit Replicate 2.3.14 the default is 10,000. For high volume configurations consider increasing to higher number. |
| OCI_COMMIT_MODE = NOWAIT BATCH | This may improve apply processing speed. Only set for non RAC target systems. See Configuration Variable Reference for more information. |
| _ENABLE_5_19_PARSE = NO | Disables processing of auditing information. This information is used by CDC/Audit function or by querying the DBRSAPPLY_PKG package on the target database (e.g. in triggers). This information includes source sid, serial#, transaction id, os user, os machine, login name. If this information is not required, then this can be disabled. Please Internal Variables for more information |
Improving performance
Following settings/tips can be applied to improve Replicate performance. Please test them first on a test system before implementing in a production environment .
| Process | Type | Description | Setting |
|---|---|---|---|
Mine |
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No CDC/AUDIT |
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Disable maintaining of session information. This information is needed only if CDC/Audit is in use to populate auxiliary fields such as source user login, program, module, action and so on.
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If _MINE_PRINT_OPEN_TRANSACTIONS is used, this feature populates the sid/serial info. |
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| _ENABLE_5_19_PARSE = NO | |
No trace files |
Disable keeping of past debug messages. So the trace files will not contain this information |
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. This is only recommended in a tested environment.
| _DISABLE_DBGPRINTF = YES |
No redo log checksums |
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Disable checking of redolog checksums. This is recommended only if
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| _MINE_CHECK_ORACHECKSUM = NO | |
No error logging to database |
| Do not log errors to DBRSCOMMON_ERRORLOG. |
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| Note that this decreases the table size and not performance. |
| _LOG_ERRORS_TO_DATABASE = NO | |
Less frequent updates of table names in list progress |
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This setting only updates table names in list progress when a log switch occurs. Note that new tables are added on the fly even with this setting. |
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The setting can confuse if there is a lot of DDL, table renames etc. Then list progress may show stale information until next log switch happens. |
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| _MINE_UPDATE_TABLIST_ON_SWITCH_ONLY = YES |
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| Apply |
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| No trace files | See Mine |
| No error logging to database | See Mine |
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| Commit Nowait |
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| Change default commit settings. Use only if target is not RAC, otherwise data loss can occur. |
| OCI_COMMIT_MODE = NOWAIT BATCH | |
| No audit info, no triggers |
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f DBRSAPPLY_PKG is used at all, apply can stop populating it's variables.
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It's used for: |
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_SET_APPPLY_PKG_AUDIT NO (on login)
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_SET_APPPLY_PKG_CONFLICT NO (on conflict)
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_SET_APPPLY_PKG_ALWAYS NO (on each change; NO is the default) | |||
Examples:
This shows an example of how to change the settings to further improve the performance:
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