Sybase IQ: Best Practices guide (free) and Manuals are now available

SAP/Sybase released SAP Sybase IQ 16 Best Practices Guide for their data warehouse product IQ.

This document presents the best practices for IQ 16. It includes recommendations for using and configuring the most important features of IQ, and precautions for avoiding and troubleshooting some of its most common issues. It also highlights IQ 16’s most significant new features and describes the latest enhancements to existing features. This document is intended to serve as a starting point for optimizing your implementation of IQ 16. As a general purpose document, it is not intended to be a comprehensive guide for every environment. Rather, it is a set of guidelines, suggestions and observations on how to better use IQ 16 and its newest capabilities

The manuals for Sybase IQ 16 are also online now.

New features in IQ 16. Most of the changes appear to revolve around multiplex (1 writer and many reader IQ instances) environments with a few minor changes such as the removal of the APPEND LOAD.

If you’re performing updates in a single server environment, you may benefit from RLV (Row Level Versioned) Store:

New in IQ 16 is the RLV (Row Level Versioned) Store – This is an in-memory delta store that is optimized for high performance row-level updates. It is currently supported only in an IQ simplex configuration (single server). The RLV store acts as a staging area for write events. If a table is enabled for the RLV store, then all LOAD TABLE, INSERT, UPDATE, and DELETE events write directly to the RLV store. In-memory data in the RLV store is automatically (and periodically) merged into the IQ main store. You can set parameters for automatic merges, and you can merge ondemand.

 

YMMV as always.

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Sybase ASE’s “lock hashtable size” is NOT just for Cluster Edition!!

The “cluster edition only” note in v15.0 documentation was a DOCUMENTATION BUG that was fixed in 15.5. Why the F is Sybase techsupport still saying it is only for cluster edition???? It was introduced in v11.9.2 more than a DECADE ago. Sybase TechSupport: read your manuals! 😉

New Functionality in Adaptive Server Enterprise 11.9.2

lock hashtable size

Summary Information
Default value 2048
Range of values 1-2147483647
Status Static
Display level Comprehensive
Required role System Administrator

The lock hashtable size parameter specifies the number of hash buckets in the lock hash table. This table manages all row, page, and table locks and all lock requests. Each time a task acquires a lock, the lock is assigned to a hash bucket, and each lock request for that lock checks the same hash bucket. Setting this value too low results in large numbers of locks in each hash bucket and slows the searches. On Adaptive Servers with multiple engines, setting this value too low can also lead to increased spinlock contention. You should not set the value to less than the default value, 2048.

lock hashtable size must be a power of 2. If the value you specify is not a power of 2, sp_configure rounds the value to the next highest power of 2 and prints an informational message.

The optimal hash table size is a function of the number of distinct objects (pages, tables, and rows) that will be locked concurrently. The optimal hash table size is at least 20 percent of the number of distinct objects that need to be locked concurrently. See “Lock Hash Table Information” for more information on configuring the lock hash table size.

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