Re: Oracle vs Sybase

I have developed client/server apps using VB/ODBC against Sybase System 10 and Oracle 7. In my humble opinion I believe that Oracle is the superior DBMS. Here are just a few reasons:

1. Higher concurrency - Locks Oracle places locks at the record level, Sybase places locks at the page level. Using Sybase System 10 we encountered numerous problems with deadlocks and poor performance due to locks. Sybase has a tendency to escalate locks meaning it will lock an entire table if locks are placed on 20% or more or its pages, Oracle does not escalate locks. Multi-Generational Architecture This last item is often overlooked, Oracle has a multi-generational architecture. This means that during a transaction when a row is written, the old row is put in an area called a rollback segment and any queries against that data that happen before the transaction is committed are able to read the data from the rollback segment. When the transaction is committed the data in the rollback segment goes away. Sybase does not have a multi-generational architecture. A transaction that writes to a Sybase table will lock an entire page of data and will not allow any queries against that data during the length of the transaction. Essentially what this means is that with Sybase, writers block readers and readers block writers. With Oracle writers do not block readers and readers do not block writers.
2. Optimizer performance - This may have changed with System 11 but as of System 10 Sybase had a notoriously poor optimizer. Sybase did a lousy job of handling sub-queries and multi-table joins of > 4 tables. This is one of the main reasons that major vendors such as SAP and PeopleSoft still cannot get their applications to work with Sybase.
3. ANSI compliance - Sybase's Transact SQL has many quirks which make it less than ANSI compliant. This may not be a big issue.
4. Cursor performance is terrible - Again an issue with System 10, maybe not 11

The benefits as I see of Sybase:
- Much easier to administer, less complicated from a DBA perspective

• Stored procedures are easier to write and are more functional.

Good luck
-Ric Received on Wed Jan 17 1996 - 00:00:00 CET