Log Record Types for Smart Large Objects
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.
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.