SQL Server 6.5 and SQL Server 7.0 Compared
January 3, 2001
Hardware and Software Requirements
To install SQL Server 6.5, you should have the following hardware:
To install SQL Server 6.5, you should have the following software:
You should have version 3.5, or 3.51, or 4.0 of the Windows NT Server or the Windows NT WorkStation operation system. You can install SQL Server 6.5 client software on the Windows 9x too.
To install SQL Server 7.0, you should have the following hardware:
SQL Server 7.0 will run under Windows 95, Windows 95 OSR2, Windows 98, Windows NT Server/Workstation 4.0 with Service Pack 4 and Windows 2000 (all editions).
SQL Server also requires Internet Explorer 4.01 with Service Pack 1 or later, or Internet Explorer 5.0 or later.
So, SQL Server 6.5 works on the more poor hardware. It worked on the Pentium 133 with 32Mb RAM (with 5-7 client machines) several years in our firm without any problems and quite quickly.
SQL Server 6.5 advantage
SQL Server 6.5 has some features, that are not supported in SQL Server 7.0.
You can backup and restore a single table.
There is no such option in SQL Server 7.0. LOAD TABLE is no longer supported. So, you should create a separated file, put table into this file, backup this file, and then you'll be able to restore it. If you have 1000's of tables, then having separate file for each table would be a nightmare!
You can use Disk Mirroring from withing SQL Server 6.5.
It's not possible with SQL Server 7.0. DISK MIRROR, DISK REMIRROR, and DISK UNMIRROR are no longer supported, because SQL Server 7.0 mirroring is no longer supported.
Microsoft recommends to use Microsoft Windows NT or hardware-based RAID in this case.
You can put tempdb in ram to increase the speed of your queries (if these queries contain subqueries, or GROUP BY, or ORDER BY clause).
This option is no longer supported in version 7.0, because, in most cases, the available RAM is best used for a data cache, rather than for a location of tempdb database.
You can use DB-Library's two-phase commit to manage transactions distributed across two or more servers.
Is no longer supported in SQL Server 7.0. Microsoft recommends to use Microsoft Distributed Transaction Coordinator (MS DTC) to accomplish simultaneous updates on two servers.
You can put table (or index) on segments using the CREATE TABLE (or CREATE INDEX) statement to increase performance.
There are no segments in SQL Server 7.0. Microsoft recommends to use filegroups in this case.
SQL Server 7.0 advantage
Full row-level locking.
SQL Server 7.0 supports full row-level locking for both data and index rows. Full row-level locking is set by default. So, many OLTP applications can experience increased concurrency, especially when applications append rows to tables and indexes.
Autogrow features for disk and memory.
SQL Server 7.0 can dynamically adjusts its memory and lock resource use. A database increases allocated resources when necessary without ever committing them and decreases the resources used when they are no longer needed.
New storage engine.
There are no database devices and segments in SQL Server 7.0, now database consists of two or more Windows files. There are three types of SQL Server database files:
Now data and log information are never mixed in the same file, and one database file can be used only by one database.
Improved Query Processing.
There are Nested-Loop joins, Merge joins and Hash joins in SQL Server 7.0, in comparison with only Nested-Loop join in SQL Server 6.5.
New data types
There are new data types:
Unicode data types take twice as much storage space as non-Unicode data types. nchar and nvarchar can store up to 4,000 of Unicode characters.
uniqueidentifier data type is used for storing a globally unique identifier (GUID).
Increasing the maximum size of the char, varchar, and varbinary data types
The maximum size of the char, varchar, and varbinary data types is now 8000 bytes, in comparison with only 255 bytes in SQL Server 6.5. So, you can use these data types instead of text or image data types more often.
Supporting Windows 9x
Now, you can install SQL Server 7.0 Desktop edition on the Windows 9x operation system.
Look here for more information about Server Improvements and New Features.