Fields and values checked in tables and indexes
This section contains tables that detail the fields and values that the CHECK TABLESPACE and CHECK INDEX commands check. For more information about these commands, see CHECK-TABLESPACE-options and CHECK INDEX options.
Each table corresponds to the type of check being performed and the type of page being checked. Each table lists the fields checked, shows the minimum level at which the check is performed, indicates the type of check performed, and describes the value against which the check is made.
CHECK TABLESPACE: page types
The following table lists all page type fields and values that the CHECK TABLESPACE option checks.
Field checked | Level | Type of check | Associated field or value | Comments |
---|---|---|---|---|
PGCOMB bit 1 | 1 | n/a | NA | Report if bit is on (page read with I/O error) |
PGCOMB bit 2 | 1 | n/a | NA | Report if bit is on (page modified by REPAIR utility) |
PGCOMB bit 4 | 1 | c/w | Page trailer byte | NA |
PGLOGRBA | 1 | c/w | Current Db2 log RBA | Checked only if PGLOGID is 0000 0001 |
PGNUMBER | 1 | c/w | Actual page number | NA |
PGFLAGS bit 1 | 1 | n/a | NA | Report if bit is on (broken page bit) |
PGFLAGS bits 2 through 8 | 1 | c/w | Page type | NA |
PGFLAGS bit 7 | 1 | c/w | Space map modified page indicator | Only on data pages |
CHECK TABLESPACE: header page
The following table lists all the header page fields and values that CHECK TABLESPACE checks.
Field checked | Level | Type of check | Associated field or value |
---|---|---|---|
HPGDBID | 1 | c/w | Db2 catalog |
HPGFLAGS bit 5 | 1 | c/w | Db2 catalog |
HPGFLAGS2 bit 1 | 1 | c/w | Db2 catalog |
HPGMAXL | 1 | c/w | Db2 catalog |
HPGNUMCO | 1 | c/w | Db2 catalog |
HPGOBID | 1 | c/w | Db2 catalog |
HPGPARTN | 1 | c/w | Db2 catalog |
HPGPGSZ | 1 | c/w | Db2 catalog |
HPGPSID | 1 | c/w | Db2 catalog |
HPGROID | 1 | c/w | Db2 catalog |
HPGRRFMT | 1 | c/w | Db2 catalog |
HPGSGNAM | 1 | c/w | Db2 catalog |
HPGSGSZ | 1 | c/w | Db2 catalog |
HPGSSNM | 1 | c/w | Db2 catalog |
HPGTBLC | 1 | c/w | Db2 catalog |
HPGTSFLOG | 1 | c/w | Db2 catalog |
HPGVCATN | 1 | c/w | Db2 catalog |
CHECK TABLESPACE: space map page
The following table lists all the space map page fields and values that CHECK TABLESPACE checks.
Field checked | Level | Type of check | Associated field or value | Comments |
---|---|---|---|---|
SEGNUM | 1 | c/w | Page size and segment size in Db2 catalog | Segmented table space only |
SEGSIZE | 1 | = | Segment size in Db2 catalog | Segmented table space only |
SEGFREE | 1 | = | Actual number of free segments | Segmented table space only |
SEGENT | 1 | = | Actual lowest free segment entry | Segmented table space only |
SEGLENT | 1 | = | Actual last formatted page | Segmented table space only |
SEGNEXT | 2 | = | Actual absolute next segment in chain | Segmented table space only |
SEGOBID | 2 | c/w | Table OBIDs from Db2 catalog for this table space | Segmented table space only |
SEGFLAG | 2 | c/w | Segment chains | Segmented table space only |
SEGFLAG bit 1 | 2 | = | 1... .... | Must be on a segment chain |
SEGFLAG bit 2 | 2 | = | 1... .... | Must not be pointed to by any other segment |
SEGFULL | 1 | c/w | Actual data page free space | Segmented table space only |
FOSMNENT | 1 | c/w | Page size from Db2 catalog | Simple or partitioned table space only |
FOSMLENT | 1 | c/w | Last formatted page within space map scope | Simple or partitioned table space only |
CHECK TABLESPACE: data page
The following table lists all the data page fields and values that CHECK TABLESPACE checks.
Field checked | Level | Type of check | Associated field or value | Comments |
---|---|---|---|---|
PGFREE | 1 | = | Sum of all hole lengths plus length of contiguous free space on this page | NA |
PGFREEP | 1 | c/w | Length of contiguous free space and size of ID map | NA |
PGHOLE1 | 1 | = | Offset of first large hole or X’0000’ if no large hole | NA |
PGMAXID | 1 | = | Actual number of ID map entries | Must be greater than zero |
PGSFLAGS | 1 | c/w | Record type | NA |
PGSLTH | 1 | c/w | Range of record lengths for rows in this table | NA |
PGSOBD | 1 | c/w | OBIDs of the tables in this table space in the Db2 catalog | NA |
PGSID | 1 | c/w | ID map entry pointing to this record | NA |
PGSOWRID | 2 | c/w | Actual overflow record | Pointer record only |
PGHLTH | 1 | = | Actual hole length | Large hole |
PGHCHAIN | 1 | = | Offset of next large hole, or X’0000’ if last on chain | Large hole |
PGHFLAGS | 1 | c/w | Size of hole | NA |
CHECK INDEX: all index page types
The following table lists all the page type fields and values that CHECK INDEX checks.
Field checked | Level | Type of check | Associated field or value | Comments |
---|---|---|---|---|
PGCOMB bit 1 | 1 | n/a | NA | Report if bit is on (page read with I/O error) |
PGCOMB bit 2 | 1 | n/a | NA | Report if bit is on (page modified by REPAIR utility) |
PGCOMB bit 4 | 1 | c/w | Page trailer byte | NA |
PGLOGRBA | 1 | c/w | Current Db2 log RBA | Checked only if PGLOGID is 0000 0001 |
PGNUMBER | 1 | c/w | Actual page number | NA |
PGFLAGS bit 1 | 1 | n/a | NA | Report if bit is on (broken page bit) |
PGFLAGS bits 2 through 8 | 1 | c/w | Page type | NA |
CHECK INDEX: index header page
The following table lists the Header page fields and values that CHECK INDEX checks.
Field checked | Level | Type of heck | Associated field or value |
---|---|---|---|
HPGDBID | 1 | c/w | Db2 catalog |
HPGPSID | 1 | c/w | Db2 catalog |
HPGSSNM | 1 | c/w | Db2 catalog |
HPGFOID | 1 | c/w | Db2 catalog |
HPGPARTN | 1 | c/w | Db2 catalog |
HPGNSUBP | 1 | = | Actual number of subpages for this index |
HPGROID | 1 | c/w | Db2 catalog |
HPGMAXL | 1 | c/w | Db2 catalog |
HPGNUMCO | 1 | = | Actual number of index key columns for this index |
HPGFLAGS bit 5 | 1 | c/w | Db2 catalog |
HPGFLAGS bit 6 | 1 | c/w | Db2 catalog |
HPGIFLGS bits 1, 2, and 3 | 1 | c/w | Db2 catalog and HPGPARTN of the header page |
HPGIFLGS bit 4 | 1 | c/w | DB2 catalog and HPGPARTN of the header page |
HPGITYPE | 1 | c/w | DB2 catalog |
HPGSGNAM | 1 | c/w | DB2 catalog |
HPGVCATN | 1 | c/w | DB2 catalog |
CHECK INDEX: space map page
The following table lists space map page fields and values that CHECK INDEX checks.
Field checked | Level | Type of check | Associated field or value |
---|---|---|---|
PPSMNE | 1 | = | X'7FC4' |
IPSLUSED | 1 | c/w | IPPSMNE |
CHECK INDEX: physical index data page header
The following table lists physical index data page header fields and values that CHECK INDEX checks.
Field checked | Level | Type of check | Associated field or value | Comments |
---|---|---|---|---|
IPFLAGS bits 4 and 5 | 1 | c/w | DB2 catalog | NA |
IPNKEYS | 1 | c/w | Number of keys | NA |
IPFREESP | 1 | c/w | Amount of free space | NA |
IPFCHSIZ | 1 | c/w | first free space entry | NA |
IPKEYLN | 1 | c/w | DB2 catalog | NA |
CHECK INDEX: leaf page
The following table lists leaf page fields and values that CHECK INDEX checks.
Field checked | Level | Type of check | Associated field or value | Comments |
---|---|---|---|---|
IPNDRIDS | 1 | c/w | Number of non-deleted RIDs | NA |
IPDRIDS | 1 | c/w | Number of deleted RIDs | NA |
IPNRIDS | 1 | c/w | Number of RIDs | NA |
IPFCESIZ | 1 | c/w | Size of free space entry | NA |