AGING Tracing

Use the ttTraceMon utility to obtain the following information:

  • When aging starts and ends

  • How many rows have been deleted by the aging subdaemon

See Implementing an Aging Policy in Your Tables in the Oracle TimesTen In-Memory Database Operations Guide.

Table 2-6 describes the AGING tracing levels. Each level with a '+' sign includes the trace information described for that level, plus all levels preceding it.

Table 2-6 AGING Tracing Levels

Level Description

1

Messages about the following events:

  • The aging subdaemon starts least recently used (LRU) or time-based aging.

  • The aging subdaemon repeats LRU aging because the LRU threshold was not met.

  • The aging subdaemon ends LRU or time-based aging.

2

+ Messages about the following events for each table:

  • Aging has started.

  • Aging has ended. The message includes the reason for ending and the total number of rows deleted.

3

+ Detailed report on how many rows were deleted during each aging cycle

4

+ Message every time the aging subdaemon wakes up

In this example, execute ttTraceMon to do an AGING trace on myDSN database. The database contains TTUSER.MYTAB table, which has a time-based aging policy. The table is described as follows: 

Command> DESCRIBE ttuser.mytab;

Table TTUSER.MYTAB:
  Columns:
   *ID                              TT_INTEGER NOT NULL
    TS                              TIMESTAMP (6) NOT NULL
  Aging use TS lifetime 3 minutes cycle 1 minute on

1 table found.
(primary key columns are indicated with *)

The table contains the following rows before the aging cycle begins:

Command> select * from TTUSER.MYTAB;
< 1, 2007-03-21 12:54:06.000000 >
< 3, 2010-03-17 08:00:00.000000 >
< 4, 2007-03-21 12:59:40.000000 >
< 5, 2007-03-21 13:00:10.000000 >
< 6, 2007-03-21 13:01:22.000000 >
5 rows found.

Execute ttTraceMon to do an AGING trace at level 3. Rather than direct the trace output to a file, read it directly from the trace buffer. Before saving the AGING trace to the buffer, use the flush command to empty the buffer. 

% ttTraceMon myDSN
Trace monitor; empty line to exit
Trace> level aging 3
Trace> flush

Display the trace information in the buffer by using the dump command. 

Trace> dump
13:16:56.802    1247 AGING    1L 2045C  17373P Entering sbAgingTB(): curTime=78
13:16:56.803    1248 AGING    2L 2045C  17373P Entering sbAgingOneTable(): 
curTime=78, ltblid= 637140
13:16:56.804    1249 AGING    3L 2045C  17373P curTime=78, 4 deleted, 1 
remaining, tbl = TTUSER.MYTAB
13:16:56.804    1250 AGING    2L 2045C  17373P Exiting sbAgingOneTable(): 
curTime=78, reason = 'no more rows', 4 deleted, 1 remaining, tbl = TTUSER.MYTAB
13:16:56.804    1251 AGING    1L 2045C  17373P Exiting sbAgingTB(): curTime=78
5 records dumped

Set AGING tracing back to its default setting (0) and exit ttTraceMon: 

Trace > level aging 0
Trace > {press ENTER – blank line}