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WELCOME TO BORLAND SQL LINKS 2.5 FOR WINDOWS
--------------------------------------------
This file contains important, late-breaking information
about Borland SQL Links for Windows, including revisions
to the documentation. Information in this file supersedes
information in the SQL Links documentation. For information
about using Borland SQL Links with Paradox or the
Database Desktop, see PDOXSQL.TXT.
TABLE OF CONTENTS
-----------------
1. TIPS FOR USING SQL LINKS
2. KNOWN PROBLEMS
3. INTERBASE SQL LINK DRIVER
4. INFORMIX SQL LINK DRIVER
5. ORACLE SQL LINK DRIVER
6. SYBASE SQL LINK DRIVER
1. TIPS FOR USING SQL LINKS
---------------------------
VENDOR DLLs. If a vendor DLL is not found on the system,
check the WINDOWS\SYSTEM directory.
USING ALIASES WITHOUT SPECIFYING A LANGUAGE DRIVER. If
no language driver is specified, the default language
driver is ASCII. Language-specific processes like
character translation, sorting and table name validation
will default to U.S. rules. For further information, see
Chapter 3 of Borland SQL Links for Windows Getting Started
and your driver's Connecting to... manual.
WORKING WITH LARGE TABLES. If you create data entry forms
on large tables you may find some performance degradation
-- particularly if the user is allowed to view
unrestricted record sets. The following suggestions may
help cut down the load on your server and help optimize
server performance:
- With large data sets, try to write applications which
access relatively few records at a time. One way to do
this within a form-based application is to create forms
which order the data by index and set range criteria to
limit the record set. (For example, instead of
creating a form which displays all orders for all
customers, write your application to limit the user's
working selection by criteria such as customer name,
state, and area code.)
- Where possible, create applications which order on
fields which were created with the REQUIRED (NOT NULL)
option. Since this field property must be specified at
the time of table creation, be sure to plan for this as
part of your application design.
WORKING WITH "SNAPSHOTS" (TABLES WITHOUT A UNIQUE INDEX
OR ROW ID). If you insert records into a "snapshot"
table, you may need to close and reopen the table to see
your additions.
2. KNOWN PROBLEMS
-----------------
UPDATING "SNAPSHOTS" (TABLES WITHOUT A UNIQUE INDEX
OR ROW ID). When working with a table that does not have
a unique index or row ID, keep the following in mind:
- The SQL Links do not support record modifications
and deletions on "snapshots" within an explicit
client transaction. Emptying tables is supported
within an explicit client transaction, but rolling
back such an operation does not update the internal
record cache.
To update the record cache, close the table and then
open it again.
3. INTERBASE DRIVER
-------------------
CONNECTING VIA FTP PC/TCP. The connection to InterBase
via FTP PC/TCP is sensitive to the amount of conventional
memory available to DOS before Windows is started. You
need at least 440 KB to use this connection protocol.
ADDITIONAL VENDOR DLLs. IUTLS.DLL and DSQL.DLL have been
added.
ADDITIONAL TRANSACTION ISOLATION LEVEL SUPPORT.
Read Committed is now supported.
SETTING INTERBASE DRIVER FLAGS. Specifying a Read Committed
transaction isolation level can result in incompatibility with applications using earlier
versions of SQL Links for InterBase. Earlier versions of SQL
Links supported Reapeatable Read only. To maintain transaction
support compatibility with earlier versions of SQL Links, set
the DRIVER FLAGS option to 512 using the BDE Configuration
Utility.
4. INFORMIX DRIVER
------------------
The Borland SQL Link Informix driver is an ESQL/C 4.x
application. Therefore, you are limited to one connection
per workstation and may encounter some limitations with the
INFORMIX LDLLSQLW.DLL (version 4.x) file.
The Borland SQL Link Informix driver supports INFORMIX-NET
PC Version 4.1. It does not work with INFORMIX-NET for
Windows Version 5.01.
BDECFG AND THE INFORMIX TSR. The Informix TSR contains
entries for HOST NAME, USER NAME, and PASSWORD that over-
ride any entries for SERVER NAME, USER NAME, and PASSWORD
that are set for the Informix driver through the BDE
Configuration Utility. This is because SERVER NAME, USER
NAME and PASSWORD cannot be set or changed from within
your BDE application. Your BDE application accesses
the database which is specified in the BDE configuration
file (usually called IDAPI.CFG), but the server name, user
name and password will always reflect what was set up
through the Informix REMSQL or SETNET programs.
For ANSI-compliant databases, the user name specified in
the configuration file is used to qualify object
names when accessing tables. If you encounter privilege
problems, make sure that the USER NAME in your
configuration file matches the USER NAME that was
specified when REMSQL or SETNET was executed.
LIMITATIONS ON OPENING TABLES. This edition of the
Informix SQL Link driver does not support opening a table
with a column name which is an Informix keyword or
function name. Some examples include MONTH, DAY, YEAR,
AVG, COUNT, ALL, and UNIQUE.
For a complete list of keywords and function names, see
your Informix documentation.
COPYING INFORMIX TABLE WITH INTERVAL COLUMN. When an
Informix table with an interval column is copied, the
destination table is created with an interval which has a
qualifier of year-to-month. If this qualifier does not
match the source table's interval qualifier, you will
receive an error during the copy.
To work around this problem, use pass-through SQL to
create the destination table with the correct interval
qualifier. Then append the contents of the source table
to the destination table.
WINDOWS MEMORY PROBLEMS AND CONNECTING TO INFORMIX.
If there are a number of Windows applications open when
you attempt to connect to Informix through your IDAPI
application, you may see Informix error message #837:
Not enough memory available.
Exit Windows, then re-start Windows and your BDE
application. If the problem continues you may need
more workstation memory.
INFORMIX ERROR MESSAGES WITH EMBEDDED FORMAT STRINGS.
For certain error messages (such as "Table not found"),
the error message Informix displays will contain an
embedded "%s" instead of a variable name.
5. ORACLE DRIVER
----------------
SUPPORT FOR QUOTED OBJECT NAMES. This release of SQL
Links supports the creation of Oracle tables with quoted
object names. Object names which are enclosed in double
quotes can contain spaces, special characters, reserved
words, or mixed case. When querying a table with special
object names, be sure to enclose the name in double
quotes; e.g.
SELECT * from "Customer"
For more information on object naming rules, see your
Oracle server documentation.
ADDITIONAL TRANSACTION ISOLATION LEVEL SUPPORT.
Repeatable Read is now supported. A Repeatable Read
transaction is always read-only.
SETTING ORACLE DRIVER FLAGS. Using mixed-case object names
can result in incompatibility with earlier versions of
SQL Links for Oracle. Earlier versions of SQL Links used
uppercase object names only. To use uppercase object names
only, set the DRIVER FLAGS option to 1 using the BDE
Configuration Utility.
Specifying a Repeatable Read transaction isolation level
can result in incompatibility with applications using earlier
versions of SQL Links for Oracle. Earlier versions of SQL
Links supported Read Committed only. To maintain transaction
support compatibility with earlier versions of SQL Links, set
the DRIVER FLAGS option to 512 using the BDE Configuration
Utility.
To use uppercase object names only AND maintain transaction
support compatibility with earlier versions of SQL Links,
set the DRIVER FLAGS option to 513 (representing 512+1)
using the BDE Configuration Utility.
TRANSLATING AN ORACLE DATE FIELD TO dBASE. In Table 1.8
of CONNECTING TO ORACLE we state that Oracle DATE fields
translate to dBASE DATE fields. They actually
translate to a dBASE character fields with date and time
information.
RUNNING NETINIT.EXE BEFORE STARTING YOUR IDAPI
APPLICATION. If you are using SQL*Net for DOS, depending
on your system memory configuration you may need to load
the Oracle NetInit program (NETINIT.EXE) before you start
your IDAPI application.
6. SYBASE DRIVER
----------------
ADDITIONAL TRANSACTION ISOLATION LEVEL SUPPORT.
An error (DBIERR_NOTSUPPORTED) is returned if Repeatable Read
is specified.
Specifying a Repeatable Read transaction isolation level can
result in incompatibility with applications using earlier
versions of SQL Links for SYBASE. Earlier versions of SQL
Links supported Read Committed only. To maintain transaction
support compatibility with earlier versions of SQL Links, set
the DRIVER FLAGS option to 512 using the BDE Configuration
Utility.
USING DEFAULT SYBASE DRIVER FLAGS SETTING. If your SYBASE
SQL Server faults while executing BLOB reads or BLOB
writes, check the SQL Link driver's DRIVER FLAGS
parameter. If DRIVER FLAGS is set to 0 (the SYBASE
default):
1. Call SYBASE Customer Support and describe the
problem, referencing Case #125046.
2. Set the DRIVER FLAGS parameter to 1. Use this
DRIVER FLAGS setting until you receive the necessary
software fix from SYBASE.
Setting DRIVER FLAGS to 1 will enable you to execute BLOB
reads and BLOB writes without causing a server fault.
This may cause the client to receive SQL Server timeouts
during BLOB writes.
To execute BLOB reads and writes AND maintain transaction
support compatibility with earlier versions of SQL Links, set
the DRIVER FLAGS option to 513 (representing 512+1) using
the BDE Configuration Utility.
MULTIPLE RESULT SETS. The Sybase SQL Link driver does not
support the use of stored procedures that return multiple
answer sets.