This is to solve a doubt that I've received.
With Microsoft Dynamics
NAV you can optimize database tables by going to FILE -->
DATABASE --> INFORMATION --> TABLES and pressing the OPTIMIZE
button:
But what is there under this task? 
When you launch the table optimization, Navision performs two tasks on SQL
Server:
- for each table, the SQL Server indexes (other than the primary
key) are rebuilt to optimize performances
- for each SIFT structure, any entries that contains zero values in a
numeric fields are removed in order to free space and to provide a more
efficient updating and summing up of SIFT information (SIFT structure are
created in order to improve some special calculations performance based on
FlowFields).
What is not involved during the optimization process is the update of SQL
Server index statistics, a process that must be always done regularly in
order to maintain good performances.
So, remember that your optimization plan must always include a phase where
you've manually to open your SQL Query Analyzer (or SQL Server Management
Studio) and launch:
- UPDATE STATISTICS [table_name] to
update statistics for a single table
- sp_updatestats to update statistics for
all the tables