7-56 IBM Informix OnLine Database Server Administrator’s Guide
Interpreting tblog Output
Record TypesIn addition to the six columns that display for every record, some record
types display additional columns of information. The information that is
displayed varies, depending on record type. A complete listing of record
types, alphabetized by type, is contained in the table onpage 7-57. The
followingparagraphs contain additional notes about specific record types or
processing conditions.
Transactions that involve dropping tables or dropping indexes generate a
PREPCOM log record when the commit begins. TheERASE,DINDEX, and
COMMIT records follow.
One record of typeCLR (24 bytes in size) is generated for each record that is
rolledback as part of processing. If the phrase “includes next record” occurs
on aCLR record, the next log record printed is included within the CLR log
record as the compensating operation. Otherwise, assume that the compen-
sating operation is the logical undo of the log record pointed to by theCLR
record.
Ifthere are active transactions at the time of a checkpoint, checkpoint records
include subentries that describe each of the active transactions using the
following columns:
■Log begin (decimal format)
■Transaction ID (decimal format)
■Unique log number (decimal format)
■Log position (hexadecimal format)
■Username
When a VARCHAR data type is included in an operation, three columns of
additionaloutput are added to the logical log record header to accommodate
the tblspace number, the rowid, and the slot-table entry number. The eight
log record types represent the following operations:
■Home page insert
■Home page delete
■Home page update
■Remainder page insert
■Remainder page delete