CoSort Pre-Sorts Can Improve Sybase Load, Reorg and Query Performance

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Improve Sybase Performance

Sybase Recommends External Sorting to Accelerate Database Loads

Challenges:

You may face one, or more, of these time-consuming issues:

• Unloading and loading of large tables
• Routine utility operations (reorgs)
• Complex queries
• Database migration or replication
• Test data generation

Specific performance diagnoses and tuning also take time, and may affect other users. Finally, stored SQL procedures may also be programmed inefficiently, require optimization, and then still take too long to run.

Solutions:

Accelerate reorgs (and unloads) by dumping table data through a SQL SELECT statement to flat files. Use the SortCL interface in CoSort product to filter, sort, join, group (and report) on the extracts in parallel. The Sybase SQL Server Reference Manual recommends external sorting to accelerate index creation during database loads. Multiple tables created quickly in query index order should help speed queries.

CoSorting data in the file system prior to loading Sybase can:

• Speed load performance between 2 and 10X
• Remove the sorting aspect of the load
• Reduce database and disk overhead
• Increase load processing rate (rows per hour)

The recommended technique says to pre-sort flat files on the clustered index. CoSort is designed for this purpose -- sorting huge files in parallel, with performance scaling linearly in volume.

Create a clustered index, but first eliminate the indexes by:

creating tables without indexes or triggers, or by dropping them from the table to be loaded.
CoSort the data on the primary index key.
bcp load the sorted table using fast bcp path (as there are no indexes on the table).
Use the SQL command CREATE INDEX, using the SORTED_DATA option, to create the clustered index.

CoSort's SortCL program can also transform and reformat data for database migrations and custom (detail, summary and delta) reports.

To rapidly populate Sybase with safe data, consider using IRI's high-volume test data generator, RowGen. RowGen uses your data models to automatically generate the test data for an entire database with referential integrity.

IRI, The CoSort Company