Table of Contents

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  1. Preface
  2. Data Replication Overview
  3. Understanding Data Replication
  4. Sources - Preparation and Replication Considerations
  5. Targets - Preparation and Replication Considerations
  6. Starting the Server Manager
  7. Getting Started with the Data Replication Console
  8. Defining and Managing Server Manager Main Servers and Subservers
  9. Creating and Managing User Accounts
  10. Creating and Managing Connections
  11. Creating Replication Configurations
  12. Materializing Targets with InitialSync
  13. Scheduling and Running Replication Tasks
  14. Implementing Advanced Replication Topologies
  15. Monitoring Data Replication
  16. Managing Replication Configurations
  17. Handling Replication Environment Changes and Failures
  18. Troubleshooting
  19. Data Replication Files and Subdirectories
  20. Data Replication Runtime Parameters
  21. Command Line Parameters for Data Replication Components
  22. Updating Configurations in the Replication Configuration CLI
  23. DDL Statements for Manually Creating Recovery Tables
  24. Sample Scripts for Enabling or Disabling SQL Server Change Data Capture
  25. Glossary

Replication Considerations for MemSQL Targets

Replication Considerations for MemSQL Targets

Review the following replication considerations for MemSQL targets:
  • When InitialSync loads data from temporary text files to MemSQL targets by using the MySQL ODBC driver, it requires audit log tables to process any SQL expressions that are defined for the source tables. You must generate the audit log tables even if the source tables with SQL expressions are mapped in SQL Apply mode.
  • If the global.insert_buffer_size runtime parameter is set to the default value of 0 to dynamically determine the appropriate number of operations that can be buffered for the target type, the Applier buffers only 1 operation because of the MySQL ODBC driver restrictions. This setting causes the Applier to apply each SQL change operation from the source to the target instead of accumulating these changes in the internal buffer first. Enter a value other than the default value only at the request of Informatica Global Customer Support.
  • MemSQL does not support the following DDL operations:
    • ALTER TABLE operations that change a column constraint from NULL to NOT NULL
    • ALTER TABLE operations that change primary keys or unique indexes
    If you enable DDL replication for a replication configuration that has a MemSQL target and determine that unsupported DDL operations might occur on the source database, set all of the following runtime parameters to 1 to avoid Applier failures: apply.skip_create_index_failed_ddl, apply.skip_drop_index_failed_ddl, and apply.skip_alter_column_failed_ddl.
  • Ensure that distribution by tables is set in one of the following ways:
    • On the
      Map Columns
      tab, select the
      Distribute by tables
      option.
    • On the
      Map Tables
      tab, click
      Settings
      to open the
      Customize Settings for the Selected Tables
      window. In the
      Distribute By
      column, select
      Tables
      .
    For MemSQL targets, the default option is distribution by rows.
  • Ensure that each Applier or InitialSync thread does not process more than 19 tables simultaneously by adjusting the values of the
    Applier threads
    and
    InitialSync threads
    fields on the
    Runtime Settings
    tab >
    General
    view.

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