SQL Server 6.5 and SQL Server 7.0 Compared

Hardware and Software Requirements

To install SQL Server 6.5, you should have the following hardware:

  • Alpha AXP, or MIPS, or Intel, or compatible platform

  • 80486, Pentium processor or higher (for Intel platform)

  • 16MB RAM (minimum), 32MB RAM and more (recommended)

  • 60MB for a minimum installation, plus 15 Mb for
    SQL Server Books Online

  • Any of the network adapters supported by Windows NT
    (or MS Loopback Adapter, if you have not network card)

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:

  • Alpha AXP, Intel or compatible platform

  • Pentium 166 MHz or higher (Pentium Pro, Pentium II and compatible)

  • 32MB RAM (minimum), 64MB RAM and more (recommended)

  • 180MB (full installation), 170MB (typical), 65MB (minimum),
    90MB (management tools only) plus 50MB for OLAP Services
    and 12MB for the English Query

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:

  • primary data files (necessary for each database, extension .mdf)

  • secondary data files (not necessary, extension .ndf)

  • log files (necessary for each database, extension .ldf)

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: nchar, nvarchar, ntext

  • uniqueidentifier data type

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

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.

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