All smart-large-object log records are the SBLOB type.
Each smart-large-object log record contains six header columns, described
in Logical-Log Record Header; the record
subtype; and additional information. The information that appears
varies, depending on record subtype.
Record Subtypes for Smart
Large Objects lists
all the smart-large-object record types. The Subtype column
describes the smart-large-object record type. The Action column
indicates the type of database server action that generated the log
entry. The Additional Columns and Format columns describe
what information appears for each record type.
Table 1. Record Subtypes for Smart
Large Objects
The table provides
record subtypes, actions, additional columns and formats for Smart
Large Objects.
Record Subtype
Action
Additional Columns
Format
CHALLOC
Allocate chunk extent.
extent [chk, page, len]
Decimal
flags
Hexadecimal
CHCOMBINE
Combine two pages in the user-data
extent list.
chunk number
Decimal
first page
Decimal
second page
Decimal
CHFREE
Frees chunk extent.
extent [chk, page, len]
Decimal
CHSPLIT
Split a page in the user-data extent
list.
chunk number
Decimal
UDFET page to split
Decimal
CREATE
Create smart large object.
smart-large-object ID [sbs, chk, page, oid]
Decimal
number of extents in lomaphdr
Decimal
DELETE
Delete a smart large object at commit.
smart-large-object ID [sbs, chk, page, oid]
Decimal
EXTEND
Add extent to an extent list of a
smart large object.
smart-large-object ID [sbs, chk, page, oid]
Decimal
extent [chk, page, len]
Decimal
lomap overflow page number
Decimal
HDRUPD
Update smart-large-object header page.
smart-large-object ID [sbs, chk, page, oid]
Decimal
old EOF offset
String
new EOF offset
String
old times
Decimal
new times
Decimal
PDELETE
Queue a smart large object for deletion at commit.
smart-large-object ID [sbs, chk, page, oid]
Decimal
PTRUNC
Queue a smart large object for truncation
at commit.
smart-large-object ID [sbs, chk, page, oid]
Decimal
old offset
String
new offset
String
REFCOUNT
Increment or decrement the reference
count of a smart large object.
smart-large-object ID [sbs, chk, page, oid]
Decimal
1 if increment; 0 if decrement
Decimal
UDINSERT,
Append new user data.
chunk
Decimal
UDINSERT_LT
page within chunk
Decimal
offset within page
Decimal
data length
Decimal
UDUPAFT,
Update user-data after-image if a
UDWRITE is too expensive.
chunk
Decimal
UDUPAFT_LT
page within chunk
Decimal
offset within page
Decimal
data length
Decimal
UDUPBEF,
Update user-data beforeimage if a
UDWRITE is too expensive.
chunk
Decimal
UDUPBEF_LT
page within chunk
Decimal
offset within page
Decimal
data length
Decimal
UDWRITE,
Update user data (difference image).
chunk
Decimal
UDWRITE_LT
page within chunk
Decimal
offset within page
Decimal
length before write
Decimal
length after write
Decimal
number of different image pieces
Decimal
For an example of smart-large-object records in onlog output,
see smart-large-object log records in the chapter on what is the logical
log in the Informix® Administrator's
Guide.
Smart-Large-Object Records in onlog
Output shows
an example of smart-large-object records in onlog output. The
first two records show that an extent was freed. The next group of
records, flanked by BEGIN and COMMIT, shows the allocation of storage
and creation of the smart large objects. Figure 1: Smart-Large-Object Records in onlog
Output