1. Logdump Reference for Oracle GoldenGate
  2. Using the Logdump Utility

1 Using the Logdump Utility

Learn how to use the Logdump utility. This utility enables you to open files, control the display, navigate through a file, and search, filter, view, and save data that's stored in a trail or extract file.

Important:

To avoid any adverse effects on the data or checkpoints in your trails, use Logdump only with guidance from an Oracle support analyst or an experienced Oracle GoldenGate user.

This chapter includes the following sections:

1.1 Getting Started with Logdump

This section introduces you to basic Logdump commands that enable you to open files, control the display, navigate through a file, and filter for specific information, among other basic tasks. It also illustrates and explains the components of a record.

Parent topic: Using the Logdump Utility

1.2 Executing Basic Logdump Tasks

The following are some basic tasks that can be performed with Logdump. For detailed information about the commands shown and other available options, see the alphabetical reference in Logdump Commands.

Parent topic: Using the Logdump Utility

1.2.1 Finding the Next Good Record Header

To find the next good record header, enter the following command:

Logdump 8> SCANFORHEADER

Alternatively, you can simply enter SFH.

Parent topic: Executing Basic Logdump Tasks

1.2.2 Finding the Beginning, Middle, and End of a Transaction

To find the beginning, middle, and end of a transaction, complete the following steps:

  1. Show headers and detail.
    Logdump 9> GHDR ON
Logdump 10> DETAIL ON
  2. Go to the next record.
    Logdump 11> N
  3. View the TransInd field in the record header. The following table explains where the record is in relation to the transaction.
    Transaction Indicator Description 
    TransInd   : .  (x00)

    First statement in transaction

    		 
    TransInd   : .  (x01)

    Statement in middle of transaction

    		 
    TransInd   : .  (x02)

    Last statement in transaction

    		 
    TransInd   : .  (x03)

    Sole statement in transaction
  4. Move through subsequent records by pressing N, and refer to the TransInd field to determine where each one is within the transaction. When TransInd is either x02 or x03, the TransInd of the next record should be x00, starting a new transaction.

Parent topic: Executing Basic Logdump Tasks

1.2.3 Scanning for the End of a Transaction

To scan for the end of a transaction, enter the following command:

Logdump 20> SCANFORENDTRANS

Alternatively, you can simply enter SFET.

The record shown will be the first one in the next transaction. To confirm, the TransInd field should be x00.

Parent topic: Executing Basic Logdump Tasks

1.2.4 Going to a Specific RBA in the File

To go to a specific RBA in the file, you can do either of the following:

  • To go to an RBA anywhere in the file:

    Logdump 35> POS rba
Logdump 36> N

    This displays the record located at that RBA.

  • To go to the first record in the file:

    Logdump 37> POS FIRST

    Alternatively, you can enter the following command:

    Logdump 37> POS 0

Parent topic: Executing Basic Logdump Tasks

1.2.5 Filtering Based on a Table or Data File Name

To filter out everything except records containing a specific NonStop data file name, enter the following command:

Logdump 60> FILTER INCLUDE FILENAME $volume.subvolume.file

To filter out everything except records containing a specific table name:

  • On a NonStop system:

    Logdump 60> FILTER INCLUDE ANSINAME catalog.schema.table

  • On a Windows or UNIX system:

    Logdump 60> FILTER INCLUDE FILENAME [container | catalog] schema.table

Now, when you use the N command, you will only see records that satisfy this filter. Conversely, to filter out records containing a specific table or file name, but show everything else, use the EXCLUDE option instead of INCLUDE.

Parent topic: Executing Basic Logdump Tasks

1.2.6 Removing the Current Filter Criteria

To remove the current filter criteria, enter the following command:

Logdump 62> FILTER CLEAR

Parent topic: Executing Basic Logdump Tasks

1.2.7 Filtering on Multiple Conditions

To filter on multiple conditions, enter one of the following commands:

  • Logdump 60> FILTER INCLUDE FILENAME $volume.subvolume...file..; FILTER RECTYPE record_type; FILTER MATCH ALL

  • Logdump 60> FILTER INCLUDE ANSINAME catalog.schema.table; FILTER RECTYPE record_type; FILTER MATCH ALL

  • Logdump 65> FILTER INCLUDE FILENAME schema.table; FILTER RECTYPE record_type; FILTER MATCH ALL

Use MATCH ANY or MATCH ALL depending on whether you want the search to match any or all of the filter conditions, respectively, when multiple conditions are specified. The preceding example filters on a name and record type, typically an operation type such as INSERT.

Parent topic: Executing Basic Logdump Tasks

1.2.8 Count the Records in a Trail File

The following command shows a count summary followed by counts for each table or data file:

Logdump 67> COUNT

Parent topic: Executing Basic Logdump Tasks

1.2.9 Saving Records to a New Trail File

To save a subset of records, enter the following command:

Logdump 68> SAVE file n RECORDS

Parent topic: Executing Basic Logdump Tasks

1.2.10 Closing the Current File and Opening the Next One in the Trail

To close the current file and open the next one in the trail, enter the following command:

Logdump 69> NEXTTRAIL

Parent topic: Executing Basic Logdump Tasks

1.2.11 Keeping a Log of Your Session

To start logging, enter the following command:

Logdump 70> LOG TO filename.txt

To write text to the log:

Logdump 71> WRITELOG "text"

To stop logging:

Logdump 72> LOG STOP

Parent topic: Executing Basic Logdump Tasks

1.2.12 Seeing the Current Logdump Environment

To see the current Logdump environment, enter the following command:

Logdump 73> ENV

This shows which features are enabled, such as filtering and header views, and it shows environment information such as the current trail and position.

Parent topic: Executing Basic Logdump Tasks

1.2.13 Checking Trail File Encryption and Decrypting a Trail File

To read or check a trail file that is encrypted by OCI KMS, first setup the OCI KMS encryption profile correctly. To know more about encryption profile and how to set up an OCI KMS encryption profile, see Apply the OCI KMS Encryption Profile for Extract.

Following are the steps to check if a trail file has been correctly encrypted and view the decrypted trail file.
  1. Set the following environment variables:
    • OGG_VAR_HOME and OGG_ETC_HOME environment variables to point to the /var and /etc directories of the corresponding Oracle GoldenGate deployment.
      export OGG_VAR_HOME=/app/Deployment/var
      export OGG_ETC_HOME=/app/Deployment/etc

    • OGG_SSL_HOME environment variable to point to the /ssl directory of the Service Manager. 

      export OGG_SSL_HOME=/app/ServiceManager/etc/ssl
  2. Start logdump.
    shell> ./logdump
  3. Open the trail file.
    open /app/Deployment/var/lib/data/trail_name
    For example:
    Logdump 47> open /app/Deployment/var/lib/data/tt000000001
    Output: 
    Current log trail file is /u02/Deployment/var/lib/data/tt000000001.
  4. Set decrypt to on state for the encryption profile. This would allow you to see the decrypted data in the trail file.
    decrypt on profile encryption_profile

    For example:

    Logdump 48> decrypt on profile OCIKMSTEST
    If the encryption profile has been setup correctly, you will see a message similar to the following in logdump:
    Using encryption profile: OCIKMSTEST

2023-06-07 23:06:20 INFO OGG-25207 Loading master encryption key from Key Management System 'ocikms'.

2023-06-07 23:06:20 INFO OGG-25851 Using encryption profile 'OCIKMSTEST'.

  5. Use the detail data and n commands to view the decrypted trail file. The detail data command displays data with hex and ASCII data values in the column list. 

    Logdump 49>detail data
Logdump 51>n

    Following is the a sample excerpt of the trail file:

    Logdump 52>n
    2023/04/04 18:56:45.205.816 Metadata             Len 382 RBA 4545 
Table Name: WPDB.U1.TCUSTMER 
*
 1)Name          2)Data Type        3)External Length  4)Fetch Offset      5)Scale         6)Level
 7)Null          8)Bump if Odd      9)Internal Length 10)Binary Length    11)Table Length 12)Most Sig DT
13)Least Sig DT 14)High Precision  15)Low Precision   16)Elementary Item  17)Occurs       18)Key Column
19)Sub DataType 20)Native DataType 21)Character Set   22)Character Length 23)LOB Type     24)Partial Type
25)Remarks
*
TDR version: 11
Definition for table WPDB.U1.TCUSTMER
Record Length: 78
Columns: 4
CUST_CODE   64      4        0  0  0 0 0      4      4      0 0 0 0 0 1    0 1   0    1       -1      0 0 0  
NAME        64     30       10  0  0 0 0     30     30      0 0 0 0 0 1    0 0   0    1       -1      0 0 0  
CITY        64     20       46  0  0 0 0     20     20      0 0 0 0 0 1    0 0   0    1       -1      0 0 0  
STATE        0      2       72  0  0 0 0      2      2      0 0 0 0 0 1    0 0   0   96       -1      0 0 0  
End of definition

    Logdump 57> n
    Oracle RBA : 0x000091.00018942.0010 

2023/04/04 18:56:42.000.000 Insert               Len    86 RBA 4994 
Name: WPDB.U1.TCUSTMER  (TDR Index: 1) 
After  Image:                                             Partition x0c   G  b   
 0000 0800 0000 0400 3030 3030 0100 2200 0000 1e00 | ........0000..".....  
 6e4f 4f43 7678 7947 6f74 456d 766c 7a4d 4543 4262 | nOOCvxyGotEmvlzMECBb  
 6f43 5751 506d 7766 7569 0200 1800 0000 1400 4956 | oCWQPmwfui........IV  
 4f5a 5849 4e44 5542 4b49 4256 4e43 4a48 4f57 0300 | OZXINDUBKIBVNCJHOW..  
 0400 0000 595a                                    | ....YZ  
Column 0 (0x0000), Length 8 (0x0008).  
 0000 0400 3030 3030                               | ....0000  
Column 1 (0x0001), Length 34 (0x0022).  
 0000 1e00 6e4f 4f43 7678 7947 6f74 456d 766c 7a4d | ....nOOCvxyGotEmvlzM  
 4543 4262 6f43 5751 506d 7766 7569                | ECBboCWQPmwfui  
Column 2 (0x0002), Length 24 (0x0018).  
 0000 1400 4956 4f5a 5849 4e44 5542 4b49 4256 4e43 | ....IVOZXINDUBKIBVNC  
 4a48 4f57                                         | JHOW  
Column 3 (0x0003), Length 4 (0x0004).  
 0000 595a                                         | ..YZ  

    Logdump 58>n
    2023/04/04 18:56:45.219.345 Metadata             Len 644 RBA 5304 
Table Name: WPDB.U1.TCUSTORD 
*
 1)Name          2)Data Type        3)External Length  4)Fetch Offset      5)Scale         6)Level
 7)Null          8)Bump if Odd      9)Internal Length 10)Binary Length    11)Table Length 12)Most Sig DT
13)Least Sig DT 14)High Precision  15)Low Precision   16)Elementary Item  17)Occurs       18)Key Column
19)Sub DataType 20)Native DataType 21)Character Set   22)Character Length 23)LOB Type     24)Partial Type
25)Remarks
*
TDR version: 11
Definition for table WPDB.U1.TCUSTORD
Record Length: 182
Columns: 7
CUST_CODE        64      4        0  0  0 0 0      4      4      0 0 0 0 0 1    0 1   0    1       -1      0 0 0  
ORDER_DATE      192     19       10  0  0 0 0     19     19     19 0 5 0 0 1    0 1   0   12       -1      0 0 0  
PRODUCT_CODE     64      8       32  0  0 0 0      8      8      0 0 0 0 0 1    0 1   0    1       -1      0 0 0  
ORDER_ID         64     50       46  0  0 0 0     50     50     50 0 0 0 0 1    0 1   2    2       -1      0 0 0  
PRODUCT_PRICE   134     10      102  2  0 0 0      8      8      8 0 0 0 0 1    0 0   3    2       -1      0 0 0  
PRODUCT_AMOUNT  134      8      114  0  0 0 0      8      8      8 0 0 0 0 1    0 0   3    2       -1      0 0 0  
TRANSACTION_ID   64     50      126  0  0 0 0     50     50     50 0 0 0 0 1    0 0   2    2       -1      0 0 0  
End of definition

Parent topic: Executing Basic Logdump Tasks

1.2.14 Getting Online Command Help

To get online command help, enter the following command:

Logdump 74> HELP

Parent topic: Executing Basic Logdump Tasks

1.2.15 To Exit Logdump

To exit Logdump, enter either of the following commands:

  • Logdump 100> EXIT

  • Logdump 100> QUIT

Parent topic: Executing Basic Logdump Tasks

1.3 Evaluating Transaction Size

Use Logdump's TRANSHIST command in conjunction with other Logdump commands to determine whether or not your applications generate large transactions and to identify their relative size. TRANSHIST causes Logdump to track the size of transactions contained in a trail file or extract file in an internal history table. The transactions are ranked in descending order of size, in bytes. When the history table is full, the smallest transaction is removed to allow a larger transaction to be added to the list.

To use statistics generated by TRANSHIST, issue the following series of commands in Logdump:

  1. Use TRANSHIST to set the size of the history table that tracks transaction size. The maximum size is 200 bytes. A value of 0 turns off the tracking.
    TRANSHIST n
  2. Use either the TRANSRECLIMIT or TRANSBYTELIMIT command to set a lower boundary for what is considered a normal sized transaction. These commands prevent normal-sized transactions from being tracked. Eliminating normal-sized transactions reduces the amount of data that must be reviewed.
    {TRANSBYTELIMIT n bytes | TRANSRECLIMIT n records}
  3. Use Logdump's COUNT command to display the statistics on transaction size, which appear at the end of the output and look like the following excerpt:
    Transactions with at least 100 records or 100000 bytes
2011/02/01 09:31:24.000.000    00:00:00.000, Seq 0, RBA 13101
   Bytes/Trans .....    1168167
   Records/Trans ...       1001
   Files/Trans .....          1
2011/02/01 09:31:35.000.000    00:00:11.000, Seq 0, RBA 1205292
   Bytes/Trans .....    1168167
   Records/Trans ...       1001
   Files/Trans .....          1

    Logdump scans the file(s) and reports the information.

  4. Use Logdump's POSITION RBA command to go to each RBA listed in the COUNT output to find out the name of the table that generated the transaction. You can group these tables into their own processing group so that they do not affect processing of other tables that generate normal sized transactions.

Parent topic: Using the Logdump Utility

1.4 Maintaining Command History

On Windows and UNIX systems, command history is stored in a file named logdump.hst. On NonStop systems, command history is stored in a file named logduhst. The file is created in the home location of the user who first started Logdump.

When Logdump starts up, it looks for the history file in one of the following locations, depending on the platform:

  • The USERPROFILE environment variable.

  • The $HOME environment variable.

  • The default $vol.subvol.

If the file exists, Logdump loads the command history into a buffer. The command history buffer holds 400 commands. Upon termination of the Logdump session, the session's history is appended to the file.

Parent topic: Using the Logdump Utility

1.5 Viewing Logdump Command Information and Syntax

To learn more about Logdump commands, see the alphabetical reference documentation in Logdump Commands.

Parent topic: Using the Logdump Utility