User Tools

Site Tools


replicator_agent_database_faq

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
replicator_agent_database_faq [2017/04/05 15:09]
willm [1.2 How does the SQL agent commit to the database ?]
replicator_agent_database_faq [2018/08/06 22:52] (current)
paul
Line 25: Line 25:
  
  
-====1.2 How does the SQL agent commit to the database ?====+====1.2 How does the SQL agent commit to the database?​====
  
 The database agent leverages the default connection commit strategy of the JDBC driver for which Oracle is auto commit. The agent does not explicitly decide when to perform a commit, the JDBC driver makes this decision. The database agent leverages the default connection commit strategy of the JDBC driver for which Oracle is auto commit. The agent does not explicitly decide when to perform a commit, the JDBC driver makes this decision.
Line 32: Line 32:
  
 <WRAP round info>​This is what typically happens. You can configure either multiple tasks to run against a single queue or you can configure multiple instances of a single task to run against a single queue. This is done primarily when throughput of the agent is an issue. Both of these configurations introduce more than a single consumer of the queue and so the order in which the database transaction occurs could be different than the order of the messages within the message store due to scheduling of the task or thread.</​WRAP>​ <WRAP round info>​This is what typically happens. You can configure either multiple tasks to run against a single queue or you can configure multiple instances of a single task to run against a single queue. This is done primarily when throughput of the agent is an issue. Both of these configurations introduce more than a single consumer of the queue and so the order in which the database transaction occurs could be different than the order of the messages within the message store due to scheduling of the task or thread.</​WRAP>​
 +
 +====1.3 Handling Schema Changes====
 +
 +The database agent handles schema changes in your instance as follows:
 +  * Columns that are added to a ServiceNow table will be automatically added to the table in the database.
 +  * When a column'​s max size is increased, the agent will automatically increase the column'​s size to the maximum size for that database. ​ In the case of MySQL, the column will automatically transition to a CLOB data type.
 +  * If a column is changed from a different data type to another data type, the data in this column will be skipped (the record itself will insert/​update all other columns).
replicator_agent_database_faq.txt ยท Last modified: 2018/08/06 22:52 by paul