11.4 pdreclaim processing results
(1) Processing results of pdreclaim (-j and -a omitted) (releasing used free pages in a table)
pdreclaim VV-RR *** DB RECLAIM *** YYYY-MM-DD hh:mm:ss [1]
TABLE NAME : USERA.TBL01 [2]
[3] [4] [5] [6] [7]
No. RDAREA NAME PAGE COUNT SEGMENT COUNT ACCESS COUNT
1 USER01 11,832 250 51,051
2 USER02 10,452 242 51,051
18244 11:02:08 un01 KFPL00739-I Pdreclaim terminated, return code=0
- Explanation:
- Header for the processing results
VV-RR: Version, revision number
YYYY-MM-DD hh:mm:ss: pdreclaim start date and time
- Name of the table that was processed
If the processing was in units of schemas, the information beginning with this item is repeated.
- Sequence numbers
- Names of the table storage RDAREAs
- Numbers of pages released
- Numbers of segments that can be released
Each RDAREA's number of segments that can be released includes not only segments that can be changed to unused segments by releasing used free pages by pdreclaim, but also segments that can be changed to unused segments by the DELETE statement for a table on which the LOCK statement was executed (executing the DELETE statement in the no-log mode automatically places the segments in LOCK-executed status).
- Number of pages accessed using the global buffer
This value includes not only the number of released pages but also the number of actual pages accessed in the extension of release processing. Note that because some management pages that are not subject to release processing might be accessed, the displayed value could be greater than the number of pages containing the corresponding resources.
(2) Processing results of pdreclaim (-j or -a specified) (releasing used free segments in a table)
pdreclaim VV-RR *** DB RECLAIM *** YYYY-MM-DD hh:mm:ss [1]
TABLE NAME : USERA.TBL01 [2]
[3] [4] [5] [6] [7]
No. RDAREA NAME PAGE COUNT SEGMENT COUNT ACCESS COUNT
1 USER01 - 250 17,017
2 USER02 - 242 17,017
18250 11:03:20 un01 KFPL00739-I Pdreclaim terminated, return code=0
- Explanation:
- Header for the processing results
VV-RR: Version, revision number
YYYY-MM-DD hh:mm:ss: pdreclaim start date and time
- Name of the table that was processed
If the processing was in units of schemas, the information beginning with this item is repeated.
- Sequence numbers
- Names of the table storage RDAREAs
- Always - when the -j option was specified; number of released pages when the -a option was specified
- Numbers of segments released
- Number of pages accessed using the global buffer
This value includes not only the number of released pages but also the number of actual pages accessed in the extension of release processing. Note that because some management pages that are not subject to release processing might be accessed, the displayed value could be greater than the number of pages containing the corresponding resources.
(3) Processing results of pdreclaim (-j and -a omitted) (releasing used free pages in indexes)
pdreclaim VV-RR *** DB RECLAIM *** YYYY-MM-DD hh:mm:ss [1]
INDEX NAME : USERA.(PRIMARY0000131193) [2]
[3] [4] [5] [6] [7] [8]
No. RDAREA NAME PAGE COUNT SEGMENT COUNT ACCESS COUNT COMPACTION
1 USER01 32 0 227 58
3 USER02 32 0 227 58
INDEX NAME : USERA.IDX01
No. RDAREA NAME PAGE COUNT SEGMENT COUNT ACCESS COUNT COMPACTION
1 USER01 891 16 6,259 1,595
3 USER02 891 16 6,259 1,595
INDEX NAME : USERA.IDX02
No. RDAREA NAME PAGE COUNT SEGMENT COUNT ACCESS COUNT COMPACTION
1 USER01 97 14 682 174
18246 11:04:10 un01 KFPL00739-I Pdreclaim terminated, return code=0
- Explanation:
- Header for the processing result
VV-RR: Version, revision number
YYYY-MM-DD hh:mm:ss: pdreclaim start date and time
- Name of the index that was processed
If multiple indexes were processed, the information beginning with this item is repeated.
- Sequence numbers
- Names of the index storage RDAREAs
- Numbers of pages released
- Numbers of segments that can be released
Each RDAREA's number of segments that can be released includes not only segments that can be changed to unused segments by releasing used free pages by pdreclaim, but also segments that can be changed to unused segments by the DELETE statement for a table on which the LOCK statement was executed (executing the DELETE statement in the no-log mode automatically places the segments in LOCK-executed status).
- Number of pages accessed using the global buffer
This value includes not only the number of released pages but also the number of actual pages accessed in the extension of release processing. Note that because some management pages that are not subject to release processing might be accessed and release processing might be performed in the upper level pages, the displayed value could be greater than the number of pages containing the corresponding resources.
- Number of pages storing the corresponding resources on which page compaction was performed
Only pages containing remaining entries are subject to page compaction.
(4) Processing results of pdreclaim (-j or -a specified) (releasing used free segments in indexes)
pdreclaim VV-RR *** DB RECLAIM *** YYYY-MM-DD hh:mm:ss [1]
INDEX NAME : USERA.(PRIMARY0000131193) [2]
[3] [4] [5] [6] [7] [8]
No. RDAREA NAME PAGE COUNT SEGMENT COUNT ACCESS COUNT COMPACTION
1 USER01 - 0 44 -
3 USER02 - 0 44 -
INDEX NAME : USERA.IDX01
No. RDAREA NAME PAGE COUNT SEGMENT COUNT ACCESS COUNT COMPACTION
1 USER01 - 16 1,204 -
3 USER02 - 16 1,204 -
INDEX NAME : USERA.IDX02
No. RDAREA NAME PAGE COUNT SEGMENT COUNT ACCESS COUNT COMPACTION
1 USER01 - 14 131 -
18252 11:05:25 un01 KFPL00739-I Pdreclaim terminated, return code=0
- Explanation:
- Header for the processing results
VV-RR: Version, revision number
YYYY-MM-DD hh:mm:ss: pdreclaim start date and time
- Name of the index that was processed
If multiple indexes were processed, the information beginning with this item is repeated.
- Sequence numbers
- Names of the index storage RDAREAs
- Always - when the -j option was specified; number of released pages when the -a option was specified
- Numbers of segments released
- Number of pages accessed using the global buffer
This value includes not only the number of released pages but also the number of actual pages accessed in the extension of release processing. Note that because some management pages that are not subject to release processing might be accessed and release processing might be performed in the upper level pages, the displayed value could be greater than the number of pages containing the corresponding resources.
- Always - when the -j option was specified
(5) Notes on the processing results
The processing results are output in the order that processing of the resources was completed.
When the -j or -a option is specified, the number of pages released as displayed by pdreclaim may not match the number of pages that can be released (Collect Prearranged Page) that is displayed as the analysis result of pddbst. Also, the number of segments that can be released (processing result of pdreclaim without the -j or -a option specified) may not match the number of segments released (processing result of pdreclaim with the -j or -a option specified). The reasons are explained below.
(a) When a page is expected to be releasable, but pdreclaim is unable to release it
- To enable concurrent execution of update processing by a UAP or utility, pdreclaim does not release any used free page or unused free segment that may result in concurrent updating. Also, the utility releases used free pages in such a manner that the number of index levels is not reduced.
- If pdrorg or pdrorg with the synchronization point specification terminates abnormally, pdreclaim does not release the first segment allocated to the corresponding table even if that segment contains no data.
- If pdreclaim is executed concurrently with update processing, a used free page or segment that was determined to be releasable may be used for update processing.
- If the number of index entries in an index leaf page is 0 (the page usage rate is treated as being 0%), pddbst assumes that the page can be released. However, of all the lower leaf pages that are pointed to from an intermediate page of an index, the leaf page with the largest key value is not released (even when the number of index entries becomes 0) until all the other lower leaf pages pointed to from the same intermediate page are released.
(b) When a page is expected to be nonreleasable, but pdreclaim can release it
- During execution of pddbst, an intermediate page of an index that forms a B-tree index structure is not counted as a releasable page, because there are lower leaf pages. pdreclaim releases an intermediate page when it has released all its lower leaf pages.
- A special page is created to manage the key values for an index that has more than 200 duplicate key values. During execution of pddbst, this management page is not counted as a releasable page (because there are lower level pages that contain duplicate key information). pdreclaim releases such a management page when it has released all of the lower level pages containing the duplicate key information.