| Oracle® TimesTen In-Memory Database Troubleshooting Guide 11g Release 2 (11.2.2) E21636-11 |
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View PDF |
| Oracle® TimesTen In-Memory Database Troubleshooting Guide 11g Release 2 (11.2.2) E21636-11 |
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|
View PDF |
The following sections in this chapter describe how to use the TimesTen utilities and other tools that are used to diagnose problems with the TimesTen database:
The ttCapture utility captures information about the configuration and state of your TimesTen system into a file that provides TimesTen technical support with a snapshot of your system at the time the ttCapture utility is running. The ttCapture utility generates a file named ttcapture.date.time.log. By default, the file is written to the directory from which you invoke the ttCapture utility. Use the ttCapture -dest option to direct the output file to be written to another directory.
If you run ttCapture again, it writes the information to a new file.
On Windows platforms, running ttCapture also produces an XML file named ttcapture.date.time.nfo that contains output from the msinfo32 utility.
When you experience a problem with a TimesTen database, run ttCapture with the DSN option for the database as soon as possible, either when you are encountering the problem or immediately afterward.
Note:
Always double-quote directory and file names in case there are spaces in the names.When you contact TimesTen technical support, upload the ttcapture.date.number.log file to the Service Request. Windows users should also upload the ttcapture.date.time.nfo file.
See "ttCapture" in the Oracle TimesTen In-Memory Database Reference for information about additional options.
The ttIsql utility enables you to interactively execute SQL statements and report status information on your TimesTen database.
All TimesTen SQL operations can be executed from a ttIsql Command> prompt.
Example 1-1 Using the ttIsql utility
To start the ttIsql utility for the demo database, enter:
% ttIsql demo
You should see output similar to the following:
Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved. Type ? or "help" for help, type "exit" to quit ttIsql. connect "DSN=demo"; Connection successful: DSN=demo;UID=testuser;DataStore=/scratch/testuser/demo; DatabaseCharacterSet=AL32UTF8;ConnectionCharacterSet=AL32UTF8;PermSize=128; TypeMode=0; (Default setting AutoCommit=1)
You can then execute SQL statements or ttIsql commands at the Command> prompt. You can also call TimesTen built-in procedures. One useful procedure is ttConfiguration. When you execute ttConfiguration, TimesTen displays the values of the connection attributes for your current database connection. For more information, see "ttConfiguration" in the Oracle TimesTen In-Memory Database Reference.
"Using the ttIsql Utility" in the Oracle TimesTen In-Memory Database Operations Guide describes how to use the most common ttIsql commands. The following ttIsql commands are commonly used when troubleshooting:
monitor formats the contents of the SYS.MONITOR table.
See "Displaying database structure information" in the Oracle TimesTen In-Memory Database Operations Guide.
dssize prints database size information.
See "Displaying database structure information" in the Oracle TimesTen In-Memory Database Operations Guide.
showplan prints the optimizer execution plans for selects, updates, and deletes in this transaction.
See "Viewing and changing query optimizer plans" in the Oracle TimesTen In-Memory Database Operations Guide.
timing prints query timing.
See "Timing ODBC function calls" in the Oracle TimesTen In-Memory Database Operations Guide.
optprofile prints the current optimizer flag settings and join order.
See "Viewing and changing query optimizer plans" in the Oracle TimesTen In-Memory Database Operations Guide.
For the full list of ttIsql features, see the lists of options and commands under the description of the ttIsql utility in the Oracle TimesTen In-Memory Database Reference.
Use the ttStatus utility to check the status of the TimesTen daemon and the state of all TimesTen connections.
Example 1-2 ttStatus shows TimesTen daemon is not running
In this example, the output from ttStatus indicates that no TimesTen daemon is running. If the daemon has stopped unexpectedly, see "No response from TimesTen daemon or subdaemon" for troubleshooting information.
On Windows:
C:\>ttStatus ttStatus: Could not connect to the TimesTen service. If the TimesTen service is not running, please start it by running "ttDaemonAdmin -start".
On UNIX platforms:
$ ttStatus ttStatus: Could not connect to the TimesTen daemon. If the TimesTen daemon is not running, please start it by running "ttDaemonAdmin -start".
Example 1-3 ttStatus shows TimesTen daemon is running
In this example, the output from ttStatus indicates that the TimesTen daemon is running. There is one database named demo.
The first line indicates that the TimesTen daemon is running as process 4579 on port 4738 for the TimesTen instance myinstance. The second line indicates the TimesTen Server is running as process 4588 on port 4740.
There are currently 12 connections to the database: one user and 11 subdaemon connections.
The restart policies for the cache agent and the replication agent in the database are set to manual.
$ ttStatus TimesTen status report as of Wed May 1 16:37:51 2013 Daemon pid 4579 port 4738 instance myinstance TimesTen server pid 4588 started on port 4740 ------------------------------------------------------------------------ Data store /scratch/testuser/demo There are 12 connections to the data store Shared Memory KEY 0x02010008 ID 7798789 PL/SQL Memory KEY 0x03010008 ID 7831558 Address 0x7fa0000000 Type PID Context Connection Name ConnID Process 4631 0x0000000009b3e800 demo 1 Subdaemon 4584 0x0000000000616460 Manager 142 Subdaemon 4584 0x000000000066d210 Rollback 141 Subdaemon 4584 0x000000000074ea00 Flusher 140 Subdaemon 4584 0x00000000007a3c90 Monitor 139 Subdaemon 4584 0x00000000007f8790 Deadlock Detector 138 Subdaemon 4584 0x000000000084f2f0 Aging 136 Subdaemon 4584 0x0000000000863db0 Log Marker 135 Subdaemon 4584 0x00000000008fcf70 IndexGC 132 Subdaemon 4584 0x00002aaabcb008d0 Checkpoint 137 Subdaemon 4584 0x00002aaabcb555f0 HistGC 133 Subdaemon 4584 0x00002aaabcc008d0 AsyncMV 134 Replication policy : Manual Cache Agent policy : Manual PL/SQL enabled. ------------------------------------------------------------------------ Accessible by group g900 End of report
Example 1-4 ttStatus shows connection to old instance
This example shows a connection to an old instance of a database. This can occur when a database is invalidated, but some users have not disconnected from the invalidated copy of the database still in memory. After all users disconnect, the memory is automatically freed.
C:\>ttStatus TimesTen status report as of Mon Aug 6 22:03:04 2012 Daemon pid 5088 port 17000 instance MYINSTANCE TimesTen server pid 4344 started on port 17002 ----------------------------------------------------------------- Data store c:\temp\sample There are no connections to the data store Obsolete or not yet active connection(s): Process 4696 context 0xd08800 name sample connid 1, obsolete connection, shmKey 'Global\DBI45b94c6f.3.SHM.4' Replication policy : Manual Cache agent policy : Manual ----------------------------------------------------------------- End of report
The TimesTen daemon and its subdaemons and agents generate error, warning, and informational messages. These messages may be useful for TimesTen system administration and for debugging applications.
By default, informational messages are stored in:
A user error log that contains information you may need to be aware of, including actions you may need to take.
A support log containing everything in the user error log plus information for use by TimesTen Customer Support.
See "Modifying informational messages" in the Oracle TimesTen In-Memory Database Operations Guide for information about configuring the logs, including their location and size.
All message categories are enabled by default, but you can also disable or explicitly enable the following categories of user error log messages for all databases or specified databases through options of the ttDaemonLog utility:
ALL (default): For all messages
CACHE: For messages from the cache agent, designated by CAC
DAEMON: For messages from the main daemon and subdaemons
DAEMONDBG: For additional information from the main daemon and subdaemons.
REPLICATION: For messages from the replication agent, designated by REP
SERVER: For messages from TimesTen Server.
See "ttDaemonLog" in Oracle TimesTen In-Memory Database Reference for information about ttDaemonLog options.
Use the ttTraceMon utility to log various trace information on a number of TimesTen components. Each TimesTen component can be traced at different levels of detail. You can list all of the traceable TimesTen components and their current tracing level by specifying ttTraceMon with the show subcommand. The full list of options for ttTraceMon is described in the "ttTraceMon" section in the Oracle TimesTen In-Memory Database Reference.
TimesTen tracing severely impacts application performance and consumes a great deal of disk space if trace output is directed to a file. In addition, when using AWT cache groups, you must restart the replication agent when trying to trace the ORACON component with ttTraceMon. Use the ttTraceMon utility only when diagnosing problems. When you are finished, reset tracing to the default values.
Example 1-5 Default trace levels for components
This example shows that the levels for most tracing components are set to level 0 (off) for the demo database. Both the ERR and DEADLOCK components are set to 1 for tracing by default. See "ERR tracing".
% ttTraceMon -e show demo AGING ... 0 API ... 0 ASYNCMV ... 0 AUTOREFRESH ... 0 CG ... 0 CGRID ... 0 CGRIDC ... 0 CKPT ... 0 DEADLOCK ... 1 EE ... 0 ERR ... 1 FLOW ... 0 HEAP ... 0 LATCH ... 0 LOCK ... 0 LOG ... 0 LOGF ... 0 OPT ... 0 ORACON ... 0 PLOAD ... 0 PT ... 0 REPL ... 0 SM ... 0 SQL ... 0 TEST ... 0 TRACE ... 0 XA ... 0 XACT ... 0
The output for most TimesTen components is of interest only to TimesTen technical support. However, the output for the SQL, API, LOCK, ERR, AGING and AUTOREFRESH components may be useful to you when you are troubleshooting application problems.
The rest of this section includes the following topics:
Start a new trace by specifying ttTraceMon datastore. For example, to start a trace on the demo database, enter:
% ttTraceMon demo Trace monitor; empty line to exit Trace >
At the Trace prompt, specify the type of trace and its level. For example, to start tracing the SQL component at level 3, enter:
Trace > level sql 3
At this point you can run your application and the TimesTen trace information is written to a trace buffer. There are two ways to read the contents of the trace buffer:
From the Trace prompt, use the outfile command to direct the trace buffer data to a file. You must do this before running your application. When writing tracing information to a file, new trace information is concatenated to the existing contents of the file.
From the Trace prompt, use the dump command to display the trace buffer data to your screen.
Note:
The contents of the trace buffer accumulate with each new trace. To clear the trace buffer, use the
flush command from a ttTraceMon prompt. Clear the buffered trace records for a specific component by specifying the component with the flush command.Each record from the trace buffer has the following format:
timestamp sequence component level connection processid operation
The fields in the records are defined as follows:
timestamp is the time at which the operation was executed.
sequence is the incremental number that identifies the trace line.
component is the TimesTen component being traced (such as SQL, API, LOCK, or ERR).
level is the trace level associated with the trace line. The range of trace levels differs by component, but for all components, the lowest trace level generates the least verbose output and highest trace level generates the most verbose output. For example, if you are tracing SQL at level 4, your output includes lines for levels 2 (prepare), 3 (execute), and 4 (open, close, fetch).
Note:
Trace levels for some components are not a continuous range of numbers. If you enter a number that does not correspond to a supported level for a component, tracing occurs at the highest supported level that is less than the number you entered. For example, if tracing levels for a component are 1, 2, 3, 4, and 6 and you enter 5, tracing events for level 1, 2, 3, and 4 are generated.connection is the internal connection ID identifying the connection that generated the trace. This number corresponds to the ConnID shown in the ttStatus output. The connection ID is also used as the first element of the transaction ID.
processid is the operating system process ID for the process that generated the trace.
operation is the operation that occurred (such as SQL statement, API operation, or error message).
For example, a line from the trace buffer after a SQL trace at level 3 might look like this:
10:39:50.231 5281 SQL 2L 1C 3914P Preparing: select cust_num from customer
Using ttTraceMon with the SQL component provides information about the SQL being prepared or executed by the TimesTen engine. Table 1-1 describes the levels for SQL tracing. Each level with a '+' sign includes the trace information described for that level, plus all levels preceding it.
| Level | Output |
|---|---|
|
2 |
SQL commands being prepared |
|
3 |
+ SQL commands being executed |
|
4 |
+ The effect of command pooling (prepares not being done because the prepared command already exists in the pool), the need for reprepares (for example, because an index was created), and commands being destroyed At this level, |
|
5 |
+ Some internal data, such as command numbers, which are not generally useful for customer-level debugging |
Note:
TimesTen recommends tracing SQL at level 3 or 4. SQL tracing does not show any information about the optimizer. Optimizer tracing is managed by a separate component (OPT) at level 4 only, and is not designed for customer use.In this example, execute ttTraceMon to do a SQL trace at level 4 on the demo database. Direct the output from the SQL trace to the SQLtrace.txt file. Then flush the buffer so that the trace does not report past SQL statements.
% ttTraceMon demo Trace monitor; empty line to exit Trace > outfile SQLtrace.txt Trace > level sql 4 Trace > flush
At this point, execute an application that includes the following SQL statement:
SELECT * FROM departments WHERE department_id = 10;
The trace information is written to the SQLtrace.txt file:
12:19:36.582 269 SQL 2L 3C 29570P Preparing: select * from departments where department_id = 10 12:19:36.583 270 SQL 4L 3C 29570P sbSqlCmdCompile ()(E): (Found already compiled version: refCount:01, bucket:28) cmdType:100, cmdNum:1000146. 12:19:36.583 271 SQL 4L 3C 29570P Opening: select * from departments where department_id = 10; 12:19:36.583 272 SQL 4L 3C 29570P Fetching: select * from departments where department_id = 10; 12:19:36.583 273 SQL 4L 3C 29570P Closing: select * from departments where department_id = 10; 5 records dumped
When the application has completed, turn off SQL tracing and exit ttTraceMon.
Trace > level sql 0
Trace > {press ENTER – blank line}
API traces are generated for database operations such as connecting to a database, changing a connection attribute, and committing a transaction. Table 1-2 describes the levels for API tracing. Each level with a '+' sign includes the trace information described for that level, plus all levels preceding it.
| Level | Output |
|---|---|
|
1 |
All rollback attempts by the subdaemon This occurs if an application exits abruptly and the subdaemon recovers its connection. |
|
2 |
+ Some low-on-space conditions |
|
3 |
+ Create, connect, disconnect, checkpoint, backup, and compact operations for the database, as well as commit and rollback for each connection, and a few other operations |
|
4 |
+ Most other operations conducted at TimesTen's internal API level It does not show numerous operations on the storage manager and indexes that are done internally. |
Note:
TimesTen recommends tracing at level 3.In this example, execute ttTraceMon to do a API trace at level 3 on the demo database. The output from the API trace is written to the APItrace.txt file. Before saving the API trace to the buffer, use the flush command to empty the buffer.
% ttTraceMon demo Trace monitor; empty line to exit Trace> outfile APItrace.txt Trace> level api 3 Trace > flush
At this point, execute the application. When the application has completed, turn off API tracing and exit ttTraceMon:
Trace > level api 0
Trace > {press ENTER – blank line}
The contents of APItrace.txt are similar to the sample output shown below. The output shows connection to the database, setting the connection character set, setting the isolation level, and committing a transaction.
11:54:26.796 1016 API 3L 2C 4848P sb_dbConnect()(X) 11:54:26.796 1017 API 3L 2C 4848P sb_dbConnCharsetSet()(E) 11:54:26.796 1018 API 3L 2C 4848P sb_dbConnSetIsoLevel()(E) 11:54:39.795 1019 API 3L 2C 4848P sb_dbConnSetIsoLevel()(E) 11:54:45.253 1020 API 3L 2C 4848P sb_xactCommitQ()(E)
Use the DEADLOCK component to trace the occurrences of deadlocks for all applications.
Table 1-3 describes the DEADLOCK tracing levels. Each level with a '+' sign includes the trace information described for that level, plus all levels preceding it.
Table 1-3 DEADLOCK tracing levels
| Level | Output |
|---|---|
|
1 |
Deadlock cycles, logged as they are discovered |
|
4, 6 |
+ Detailed information about how the deadlock is detected |
In this example, execute ttTraceMon to do a DEADLOCK trace at level 1, which is the default, on myDSN database.
Make two connections to myDSN. For the first connection, autocommit is on. Create table test and insert two rows. Then, set autocommit off and update the x1=1 row of table test. Because autocommit is off, the row is not inserted into the table until the commit. A lock is held until the transaction is committed or rolled back.
Command> create table test (x1 int unique, y1 int); Command> insert into test values (1,1); 1 row inserted. Command> insert into test values (2,2); 1 row inserted. Command> autocommit 0; Command> update test set y1=y1 where x1=1; 1 row updated.
For the second connection to myDSN, autocommit is set to off. Update the x1=2 row of table test.
Command> autocommit 0; Command> update test set y1=y1 where x1=2;1 row updated.
Now, create a deadlock situation by executing update statements in both connections for rows that are locked by each other. The first connection executes an update against the row where x1=2.
Command> update test set y1=y1 where x1=2; 6003: Lock request denied because of time-out Details: Tran 2.1 (pid 32750) wants Un lock on rowid BMUFVUAAAAaAAAAETk, table ME.TEST. But tran 3.2 (pid 32731) has it in Xn (request was Xn). Holder SQL (update t1 set y1=y1 where x1=2) The command failed.
The second connection executes an update against the row where x1=1.
Command> update test set y1=y1 where x1=1; 6002: Lock request denied because of deadlock Details: Tran 3.2 (pid 32731) wants Un lock on rowid BMUFVUAAAAaAAAADzk, table ME.TEST. But tran 2.1 (pid 32750) has it in Xn (request was Xn). Holder SQL (update t1 set y1=y1 where x1=1) The command failed.
Use the flush command to empty the buffer.
% ttTraceMon myDSN Trace monitor; empty line to exit Trace> flush
The trace buffer contains the following information showing all level 1 deadlock traces, as evidenced by '1L'.
Trace> dump 09:50:26.444 13 DEADLOCK 1L 2036C 3484P edge 1: xid 3.2, cid 3, <Row BMUFVUAAAAaAAAADzk,0x8c5 74(574836)> 0 cnt=1 , Tbl 'T1', SQL='update t1 set y1=y1 where x1=1' 09:50:26.455 14 DEADLOCK 1L 2036C 3484P edge 0: xid 2.1, cid 2, <Row BMUFVUAAAAaAAAAETk,0x8c5 74(574836)> 0 cnt=1 , Tbl 'T1', SQL='update t1 set y1=y1 where x1=2' 09:50:26.455 15 DEADLOCK 1L 2036C 3484P Victim: xcb:3.2, SQL='update t1 set y1=y1 where x1=1'
If you want more information, set DEADLOCK tracing to a higher value. For example, the following sets DEADLOCK tracing to level 4 in ttTraceMon:
Trace > level deadlock 4
Use the LOCK component to trace the locking behavior of your application to detect trouble with deadlocks or lock waits. LOCK tracing generates a great deal of volume, so it is important to choose the appropriate level of tracing. Level 3, for example, begins to generate a large number of traces, as traces are written for fairly common events. Also, the traces themselves may be hard to read in places. If you cannot discern enough information, contact TimesTen technical support for more information.
Table 1-4 describes the LOCK tracing levels. Each level with a '+' sign includes the trace information described for that level, plus all levels preceding it.
| Level | Output |
|---|---|
|
1 |
Deadlock cycles as they are discovered |
|
2 |
+ Failures to grant locks for any reason |
|
3 |
+ Lock waits (which may or may not be granted) |
|
4 |
+ All lock grants/releases, some routine calls, and the mechanism of the deadlock detector |
|
6 |
+ Each step in cycle traversal |
In this example, execute ttTraceMon to do a LOCK trace at level 4 on myDSN database.
Make two connections to myDSN. For the first connection, set autocommit on. Create table test and insert three rows. Create a materialized view using table test.
Turn on tracing at level 4 and use the flush command to empty the buffer.
% ttTraceMon myDSN Trace monitor; empty line to exit Trace> level lock 4 Trace> flush
For the second connection to myDSN, set autocommit off. Insert a row into table test. Because autocommit is off, the row is not inserted into the table until the commit. A lock is held until the transaction is committed or rolled back.
If the dump command is used to display the contents of the trace buffer, there are no records in the trace buffer:
Trace> dump 0 records dumped
From the first connection, try to drop the materialized view. The view cannot be dropped because there is a transaction that has not been committed or rolled back:
Command> drop materialized view v; 6003: Lock request denied because of time-out Details: Tran 3.71 (pid 24524) wants Sn lock on table TTUSER.TEST. But tran 1.42 (pid 24263) has it in IXn (request was IXn). Holder SQL (insert into test values (100);) The command failed.
The trace buffer contains the following information:
Trace> dump 20:09:04.789 174759 LOCK 3L 3C 24524P ENQ: xcb:00003 <Tbl 0x9b894,0x0> 0+Sn=>SL activity 0 Sn cnt=0; Holder xcb:00001 IXn 20:09:04.789 174760 LOCK 3L 3C 24524P Connection 3 scheduled for sleep 20:09:04.789 174761 LOCK 3L 3C 24524P Connection 3 sleeping 20:09:14.871 174762 LOCK 3L 2047C 24237P Connection 3 timed out 20:09:14.871 174763 LOCK 3L 2047C 24237P Connection 3 woken up 20:09:14.871 174764 LOCK 3L 3C 24524P Connection 3 awake 20:09:14.871 174765 LOCK 2L 3C 24524P ENQ: xcb:00003 <Tbl 0x9b894,0x0> 0+Sn=>TM activity 0 Sn cnt=1; Holder xcb:00001 IXn 7 records dumped
When finished with the trace, set LOCK tracing back to its default setting (0) and exit ttTraceMon:
Trace > level lock 0
Trace > {press ENTER – blank line}
It may be useful to trace the ERR component. For example, an ERR trace at level 4 shows all of the error messages that are pushed in the TimesTen direct driver (not all errors are output to the user because they are handled internally). ERR tracing at level 1 is the default. No output is written for ERR tracing at level 2 and 3.
Table 1-5 describes ERR tracing levels. Each level with a '+' sign includes the trace information described for that level, plus all levels preceding it.
| Level | Output |
|---|---|
|
1 (set by default) |
Fatal errors |
|
4 |
+ All other error messages, many of which are handled internally by TimesTen |
In this example, execute ttTraceMon to do a ERR trace at level 4 on myDSN database.
First, create a table:
Command> create table test (id tt_integer);
Next, turn on tracing at level 4. Rather than direct the trace output to a file as in the previous examples, read it directly from the trace buffer. Before saving the ERR trace to the buffer, use the flush command to empty the buffer.
% ttTraceMon myDSN Trace monitor; empty line to exit Trace> level err 4 Trace> flush
Now execute a SQL script with three errors in it. The errors are:
Creating a table with the same name as an existing table
Using incorrect syntax to insert values into the table
Inserting CHAR data into a TT_INTEGER column
Command> create table test (id tt_integer);
2207: Table TEST already exists
The command failed.
Command> insert into test values 'abcd');
1001: Syntax error in SQL statement before or at: "'abcd'", character position:
25
insert into test values 'abcd');
^^^^^^
The command failed.
Command> insert into test values ('abcd');
2609: Incompatible types found in expression
The command failed.
The trace information is written to the trace buffer. Display it by using the dump command.
Trace> dump
19:28:40.465 174227 ERR 4L 1C 24263P TT2207: Table TEST already exists
-- file "eeDDL.c", lineno 2930, procedure "sbEeCrDtblEval()"
19:28:51.399 174228 ERR 4L 1C 24263P TT1001: Syntax error in SQL
statement before or at: "'abcd'", character position: 25
insert into test values 'abcd');
^^^^^^
-- file "ptSqlY.y", lineno 6273, procedure "reserved_word_or_syntax_error"
19:29:00.725 174229 ERR 4L 1C 24263P TT2609: Incompatible types found
in expression -- file "saCanon.c", lineno 12618, procedure "sbPtAdjustType()"
3 records dumped
Set ERR tracing back to its default setting (1) and exit ttTraceMon:
Trace > level err 1
Trace > {press ENTER – blank line}
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 aging in your tables" in the Oracle TimesTen In-Memory Database Operations Guide.
Table 1-6 describes the AGING tracing levels. Each level with a '+' sign includes the trace information described for that level, plus all levels preceding it.
Table 1-6 AGING tracing levels
| Level | Description |
|---|---|
|
1 |
Messages about the following events:
|
|
2 |
+ Messages about the following events for each table:
|
|
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}
Use the ttTraceMon utility to obtain information about the progress of autorefresh operations for cache groups with the AUTOREFRESH cache group attribute.
See "AUTOREFRESH cache group attribute" in the Oracle TimesTen Application-Tier Database Cache User's Guide.
Table 1-7 describes AUTOREFRESH tracing levels. Each level with a '+' sign includes the trace information described for that level, plus all levels preceding it.
Table 1-7 AUTOREFRESH tracing levels
| Level | Description |
|---|---|
|
1 |
Autorefresh summary for the interval:
Note: Times and information about root table rows are reported for full autorefresh. |
|
2 |
+ Autorefresh summary at the cache group level:
Note: Times and information about root table rows are reported for full autorefresh. |
|
3 |
+ Autorefresh summary at the table level:
|
|
4 |
+ Autorefresh details for each table:
|
Example 1-12 AUTOREFRESH trace
In this example, use the ttTraceMon utility to trace autorefresh operations on the cgDSN database. When the trace level is set to 1, the displayed information is similar to the output of the ttCacheAutorefreshStatsGet built-in procedure.
% tttracemon cgDSN Trace monitor; empty line to exit Trace> level autorefresh 1 Trace> dump 08:56:57.445 19398 AUTOREFRESH 1L 5C 32246P Autorefresh number 1415 started for interval 60000 08:56:57.883 19419 AUTOREFRESH 1L 5C 32246P Duration For Interval 60000ms: 420 08:56:57.883 19420 AUTOREFRESH 1L 5C 32246P Num Rows For Interval 60000ms: 0 08:56:57.883 19421 AUTOREFRESH 1L 5C 32246P Num Root Rows For Interval 60000ms: 0 08:56:57.883 19422 AUTOREFRESH 1L 5C 32246P Cumulative Rows for Interval 60000ms: 11587 08:56:57.883 19423 AUTOREFRESH 1L 5C 32246P Cumulative Root Rows for Interval 60000ms: 1697 08:56:57.883 19424 AUTOREFRESH 1L 5C 32246P Autorefresh number 1415 ended for interval 60000ms successfully. 7 records dumped
Tracing at level 4 produces additional information about autorefresh operation 1415. Information about autorefresh is provided for the testuser.readcache cache group, the testuser.readtab root table and the autorefresh interval.
Trace> level autorefresh 4 Trace> dump 08:56:57.445 19398 AUTOREFRESH 1L 5C 32246P Autorefresh number 1415 started for interval 60000 08:56:57.471 19399 AUTOREFRESH 2L 5C 32246P Autorefresh started for cachegroup TESTUSER.READCACHE 08:56:57.471 19400 AUTOREFRESH 3L 5C 32246P Incremental autorefresh started for table TESTUSER.READTAB 08:56:57.471 19401 AUTOREFRESH 4L 5C 32246P Autorefresh Query: SELECT L."COL_10", X."COL_20", X.ft$NotDelete, Z.rowid FROM (SELECT DISTINCT "COL_10" FROM "TESTUSER"."TT_06_454854_L" WHERE logseq >:logseq AND ft_cacheGroup <> 100000000000*1844259679+-299200618) L,(SELECT "TESTUSER"."READTAB"."COL_10", "TESTUSER"."READTAB"."COL_20", 1 AS ft$NotDelete FROM "TESTUSER"."READTAB", "TESTUSER"."T1" WHERE "TESTUSER"."READTAB"."COL_10" = "TESTUSER"."T1"."COL_10") X, "TESTUSER"."READTAB" Z WHERE L ."COL_10" = X."COL_10" (+) AND X."COL_10" = Z."COL_10" (+), logseq: 7 08:56:57.870 19402 AUTOREFRESH 3L 5C 32246P Duration for table TESTUSER.READTAB: 70 08:56:57.870 19403 AUTOREFRESH 3L 5C 32246P Num Rows for table TESTUSER.READTAB: 1 08:56:57.870 19404 AUTOREFRESH 3L 5C 32246P Cumulative rows for table TESTUSER.READTAB: 1559 08:56:57.870 19405 AUTOREFRESH 4L 5C 32246P Autorefresh Query Execute duration for table TESTUSER.READTAB: 60 08:56:57.870 19406 AUTOREFRESH 4L 5C 32246P Autorefresh Query Fetch duration for table TESTUSER.READTAB: 0 08:56:57.870 19407 AUTOREFRESH 4L 5C 32246P Autorefresh Query Apply duration for table TESTUSER.READTAB: 0 08:56:57.870 19408 AUTOREFRESH 4L 5C 32246P Max logseq applied for table TESTUSER.READTAB: 8 08:56:57.870 19409 AUTOREFRESH 4L 5C 32246P Autorefresh Query Execute duration for 7 child(ren) table(s): 32 08:56:57.870 19410 AUTOREFRESH 4L 5C 32246P Autorefresh Query Fetch duration for 7 child(ren) table(s): 0 08:56:57.870 19411 AUTOREFRESH 4L 5C 32246P Autorefresh Query Apply duration for 7 child(ren) table(s): 0 08:56:57.870 19412 AUTOREFRESH 3L 5C 32246P Incremental autorefresh ended for table TESTUSER.READTAB 08:56:57.872 19413 AUTOREFRESH 2L 5C 32246P Duration For Cache Group TESTUSER.READCACHE: 1020 08:56:57.872 19414 AUTOREFRESH 2L 5C 32246P Num Rows For Cache Group TESTUSER.READCACHE: 1 08:56:57.872 19415 AUTOREFRESH 2L 5C 32246P Num Root Rows For Cache Group TESTUSER.READCACHE: 0 08:56:57.872 19416 AUTOREFRESH 2L 5C 32246P Cumulative Rows for Cache Group TESTUSER.READCACHE: 11776 08:56:57.872 19417 AUTOREFRESH 2L 5C 32246P Cumulative Root Rows for Cache Group TESTUSER.READCACHE: 1697 08:56:57.872 19418 AUTOREFRESH 2L 5C 32246P Autorefresh ended for cache group TESTUSER.READCACHE 08:56:57.883 19419 AUTOREFRESH 1L 5C 32246P Duration For Interval 60000ms: 420 08:56:57.883 19420 AUTOREFRESH 1L 5C 32246P Num Rows For Interval 60000ms: 0 08:56:57.883 19421 AUTOREFRESH 1L 5C 32246P Num Root Rows For Interval 60000ms: 0 08:56:57.883 19422 AUTOREFRESH 1L 5C 32246P Cumulative Rows for Interval 60000ms: 11587 08:56:57.883 19423 AUTOREFRESH 1L 5C 32246P Cumulative Root Rows for Interval 60000ms: 1697 08:56:57.883 19424 AUTOREFRESH 1L 5C 32246P Autorefresh number 1415 ended for interval 60000ms successfully. 27 records dumped
Set AUTOREFRESH tracing back to its default setting (0) and exit ttTraceMon:
Trace > level autorefresh 0
Trace > {press ENTER – blank line}
The ttXactAdmin utility displays ownership, status, log and lock information for each outstanding transaction. You can also use it to show all current connections to a database. The ttXactAdmin utility is useful for troubleshooting problems with replication, XLA, and asynchronous writethrough cache groups.
Example 1-13 Using ttXactAdmin to diagnose a lock timeout
Use ttXactAdmin to diagnose a lock timeout. Consider two connections that are trying to update the same row. The following transaction by Connection 1 is in progress:
UPDATE table1 SET c1 = 2 WHERE c1 = 1;
Connection 2 attempts to make the following update:
UPDATE table1 SET c1 = 3 WHERE c1 = 1;
Connection 2 receives the following error:
6003: Lock request denied because of time-out Details: Tran 2.3 (pid 2880) wants Un lock on rowid 0x00156bbc, table TTUSER.TABLE1. But tran 1.21 (pid 2564) has it in Xn (request was Xn). Holder SQL (update table1 set c1 = 2 where c1 = 1;) The command failed.
The details of the error indicate that transaction 1.21 has a lock on row 0x00156bbc, the row that transaction 2.3 wants to update. ttXactAdmin displays this information in output that pertains to actions in the entire database:
$ ttXactAdmin myDSN
2011-03-07 12:57:41.237
c:\datastore\myDSN
TimesTen Release 11.2.2.0.0
Outstanding locks
PID Context TransID TransStatus Resource ResourceID Mode Name
Program File Name: ttIsql
2564 0xeeb9a8 1.21 Active Database 0x01312d00 IX
Row 0x00156bbc Xn TTUSER.TABLE1
Table 1910868 IXn TTUSER.TABLE1
Program File Name: ttIsql
2880 0xeeb9a8 2.3 Active Database 0x01312d00 IX
Table 1910868 IXn TTUSER.TABLE1
Command 19972120 S
Awaiting locks
PID Context TransID Resource ResourceID RMode HolderTransID HMode Name
2880 0xeeb9a8 2.3 Row 0x00156bbc Un 1.21 Xn TTUSER.TABLE1
2 outstanding transactions found
See "ttXactAdmin" in the Oracle TimesTen In-Memory Database Reference.
On Windows, use the ODBC trace facility to verify the sequence and content of your commands. The ODBC trace facility works only if you have linked your application with the ODBC Driver Manager. Enable tracing by double-clicking ODBC in the Control Panel. This opens the ODBC Data Source Administrator. Choose the Tracing tab.
On UNIX platforms, ODBC tracing is available only when using a driver manager. To turn on tracing, set the Trace and TraceFile attributes.
Network management software uses SNMP (Simple Network Management Protocol) to query or control the state of network devices such as routers and switches. These devices can generate alerts called traps to inform the network management systems of problems.
TimesTen sends SNMP traps for particular critical events to help facilitate user recovery mechanisms. These events are also recorded in the support log. Exposing them through SNMP traps enables network management software to take immediate action.
How to configure TimesTen to generate SNMP traps and how to receive the traps is described in "Diagnostics through SNMP Traps" in the Oracle TimesTen In-Memory Database Error Messages and SNMP Traps.
Each TimesTen database contains a group of system tables that store metadata about the current state of the database. The system tables are described in "System Tables" in the Oracle TimesTen In-Memory Database System Tables and Views Reference.
Note:
You can executeSELECT statements on a system table, but you cannot execute a statement such as INSERT, UPDATE or DELETE on these tables.Use the system table SYS.SYSTEMSTATS to view database metrics. In addition, the ttStats utility enables you to monitor database metrics and to take and compare snapshots of metrics. For more information, see "SYS.SYSTEMSTATS" in the Oracle TimesTen In-Memory Database System Tables and Views Reference, "ttStats" in the Oracle TimesTen In-Memory Database Reference, and "TT_STATS" in the Oracle TimesTen In-Memory Database PL/SQL Packages Reference.
You can also view the SYS.MONITOR table, which contains statistics about certain events that have occurred since the first connection to the database. For example, the SYS.MONITOR table contains information about the number of connections to the database; the number of checkpoints taken; the size of the database; and the amount of memory currently in use. Check the contents of the SYS.MONITOR table by executing SELECT statements on the columns or by using the ttIsql monitor command. For an example of how to use the ttIsql monitor command, see "Using the ttIsql Utility" in the Oracle TimesTen In-Memory Database Operations Guide.
The query optimizer is an important tool for performance tuning.
For details about using the query optimizer, see:
"The TimesTen Query Optimizer" in the Oracle TimesTen In-Memory Database Operations Guide
"Viewing and changing query optimizer plans" in the Oracle TimesTen In-Memory Database Operations Guide
If you find that a given query runs more slowly than expected, confirm that the query optimizer has the latest statistics for the tables in your query, as described in "Update query optimizer statistics". If, after updating your statistics, your query still runs too slowly, it is possible that the TimesTen optimizer is not choosing the optimal query plan to answer that query. Under these circumstances, you can adjust how the optimizer generates a plan by using the ttOpt procedures described in "Modifying plan generation" in the Oracle TimesTen In-Memory Database Operations Guide. You can also use statement level optimizer hints to influence the optimizer at the statement level. For more information, see "Statement level optimizer hints" in the Oracle TimesTen In-Memory Database SQL Reference.
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