PC Plus SuperCD (UK) 1995 August/PC Plus Super CD (Issue 106) (PCP106) (August 1995).iso/qe6/qdread.me

Text File | 1994-08-09 | 18.4 KB | 484 lines

        Q+E Database Drivers
        for INTERSOLV Q+E Version 6.0
        August 1994

This READ.ME file contains information not included in the Q+E
Database Driver Reference. This file contains information about
the following topics:

New Features in the Q+E Drivers
    Renamed Drivers
    New Database Systems Supported
    Database Systems No Longer Supported
For Btrieve Users
For dBASE Users
For INGRES Users
For NetWare SQL Users
For Teradata Users
For Oracle 7 Users
For Paradox Users
For SQL Server Users
    Problems with Catalog Stored Procedures?
    Use Statements
For Sybase System 10 Users
    Before Using the System 10 Driver
    Required Execute Access to TEMPDB
    Data Type Information
For Text File Users
For Users of Extend Products
Aborting a Long-Running Query on a Flat File
Loading INFORMIX and NetWare SQL DLLs Correctly
Solving Connection Problems with QEDLLMGR
Compatibility with Third-Party Drivers
     Microsoft Access Driver
     Microsoft Text Driver
     Lotus Notes Driver
     Microsoft SQLServer Driver
     Microsoft Oracle Driver

A Windows Help version of this file is available in the file
QDREADME.HLP.

For information supplemental to the INTERSOLV Q+E User's
Manual, see the file READ.ME or README.HLP.


    New Features in the Q+E Drivers

The following list summarizes the new features of the drivers that
are distributed with Q+E version 6.0:

Renamed Drivers
---------------
MDI.The DB2 driver is now called the MDI driver. You can access DB2
database systems through this driver. You cannot access Teradata
database systems.

HP ALLBASE/SQL and HP IMAGE/SQL. In Q+E revision 5.x, the SQLBase driver
supported HP ALLBASE/SQL and HP IMAGE/SQL. In this revision of Q+E, the
ALLBASE driver supports these database systems.

OS/2 Database Manager. The OS/2 Database Manager driver is now called the
DB2/2 driver.

New Database Systems Supported
------------------------------
Clipper files. The dBASE driver now supports Clipper files.

DB2/6000 database and gateway. The DB2/2 driver (formerly called the OS/2
Database Manager driver) now supports DB2/6000 database systems and
SQL/400, MVS DB2, and SQL/DS through the DDCS/60000 gateway.

FoxPro and FoxBASE. The dBASE driver now supports FoxPro and FoxBASE files,
as well as FoxPro and FoxBASE-compatible locking.

INFORMIX 5. The new INFORMIX 5 driver provides multiple connections from a
single workstation and supports more than 64K of data. (You can access
INFORMIX 5 files with the INFORMIX 4 driver, but it does not provide these
features.)

INGRES 6.4/04. The new INGRES 6.4/04 driver supports INGRES 6.4/04. To use
this driver, double-click the ODBC icon in the Windows Control Panel. A
list of data sources appears. Click Add. The list of installed drivers
appears. Select Q+E INGRES 6.4/04. The section "For INGRES Users" lists
the system requirements and known issues.

Oracle 7. The new Oracle 7 driver supports Oracle 7 database systems.

Sybase System 10. The new Sybase System 10 driver supports the Sybase
System 10 database system.

Database Systems No Longer Supported
------------------------------------
The Tandem NonStop SQL database system is no longer supported.


        For Btrieve Users

There are two versions of WBTRCALL.DLL: networked and not networked.
INTERSOLV supplies the not networked version when you install the Btrieve
driver. If you want network access, you must get the networked version from
Novell.

If you are already using networked Btrieve, do not install the INTERSOLV
version of WBTRCALL.DLL, because it does not support network access. When
the Setup program asks whether you wish to overwrite WBTRCALL.DLL, answer
No.


        For dBASE Users

- The dBASE driver supports FoxBase and FoxPro tables and indexes.

- The dBASE driver offers five different locking schemes: dBASE, Clipper,
  Fox, Q+E, and Q+EVirtual.

- The CREATE INDEX statement accepts dBASE-style index expressions as an
  alternative to the comma-separated list of column names.

- Concatenated indexes with numeric or date types no longer require the STR
  or DTOS function to be specified in the Where clause to use the index.
  For example, an index based on STR(col1,4)+STR(col2,4) previously required
  a Where clause that specifically used the STR function. So a Where clause
  like
  WHERE STR(col1,4) = '  45' and STR(col2,4) = '  68'
  should be replaced with
  WHERE col1 = 45 and col2 = 68

- File locking has changed. With previous versions of the dBASE driver that
  had file locking enabled, the file lock was placed when a table was
  opened and released when the table was closed. With this version of the
  dBASE driver, file locks are held for a shorter period. The file lock is
  obtained during the first modification to the table in a transaction and
  is held until the Commit. File locks do not prevent readers from
  accessing a table nor do they prevent new records from being inserted
  into the table.

- The Order By clause now takes advantage of indexes to achieve ordering.
  This optimization should boost performance.

- A subquery can now be specified in the Set clause of Update statements.

- Indexes that contain FOR expressions will be properly maintained.

- Indexes with FOR expressions are ignored during query optimization.


        For INGRES Users

A driver for INGRES 6.4/04 is now available. System requirements are as
follows:

- Installed and configured INGRES client software INGRES 6.4/04 (net.win/00)
  or later.

- Three INGRES patches, with these (or later) dates:
  #2766: IIW3GCC.DLL, 11-09-93
  #2894: FRONTCL.DLL, 12-03-93
  #3054: IIW3CL.DLL, 02-17-94.

You can get these patches from your INGRES customer support representative.
INTERSOLV recommends that you monitor the INGRES Technical Support BBS,
at [phone] 9600bps/N81, for additional patches as they become
available.


The following known issues are related to this driver:

- INGRES bugs #60353 and #60729.
  Both relate to improper termination of INGRES connections under error
  conditions. Both can cause GPFs in IIW3GCC.DLL and require exiting Windows
  before reconnecting. As a workaround, set II_GCC_UNLOAD to FALSE in
  AUTOEXEC.BAT and CONFIG.ING. However, if you still encounter this problem,
  run chkdsk or another disk repair utility as a precaution.

- Under some conditions, large numeric values are truncated to 0.0. This can
  be reproduced using only INGRES ISQL, and is under investigation by INGRES.

- Under some conditions, degenerate Where clauses (for example, Where 1 = 0)
  can cause unpredictable cursor behavior. This cannot be reproduced using
  INGRES ISQL but can be reproduced by a few lines of embedded SQL. INGRES
  has identified this problem and plans to correct it in the upcoming
  6.4/04 (srv/01) Program Update Release. Users of Q+E will need this
  Program Update Release.


        For NetWare SQL Users

If you lock a record, Q+E may use a current of cursor operation to
modify or delete a row. The NetWare SQL driver simulates a current
of cursor operation. This simulation may generate a large Where clause
even though Q+E is using only one column as the key. NetWare SQL limits
the number of characters in a Where clause. The workaround is to disable
current of cursor operations when the user locks a record before
updating it. To do this, add the line

QeDontUseCOC=1

to the NetWareSQL section of the ODBC.INI file.


        For Teradata Users

Contrary to the information in the Database Driver Reference, you cannot
use the MDI driver for Teradata access. You receive syntax errors when
the application makes catalog function calls.


        For Oracle 7 Users

Oracle 7 users should be aware of possible memory leaks in the most recent
version of the Oracle 7 client API dynamic link library, ORA7WIN.DLL, which
is dated 11/29/93. If you are using this DLL, try to limit the number of
logons to Oracle 7. You can use QEDLLOAD.EXE to load ORA7WIN.DLL into memory.
Or, you can try using the older version of ORA7WIN.DLL, (which you can download
from our Bulletin Board system), but we cannot guarantee the functionality of
the older version.

We are working with Oracle to resolve this problem. When we have a solution, we
will post it on our BBS.


        For PARADOX Users

The Order By clause now takes advantage of indexes to achieve ordering.
This optimization should boost performance.

A subquery can now be specified in the Set clause of Update statements.


        For SQL Server Users

The following topics apply to users of Microsoft SQL Server and Sybase
SQL Server.

Problems with Catalog Stored Procedures?
----------------------------------------
If you have problems with the catalog functions returning incorrect
data, you may need to upgrade your catalog stored procedures. In
particular, the SQL Server version 4.2 procedures do not provide
enough information for many of our catalog functions to work
properly. Make sure you have installed the latest version of the
stored procedures, which are available from your database vendor.
Refer to your SQL Server documentation for more information.

Use Statements
--------------
The SQL Server and Sybase drivers now let a user perform a Use statement
to change the current database. A Use statement affects every statement
associated with the current connection. Any future call to SQLExecute or
one of the catalog routines with Qualifier set to NULL or % is executed
on the new database. The exception to this rule is that some prepared
Select statements may have already been executed.

Users may also execute catalog functions using any valid database name
as the qualifier. This does not affect the user's current database or
any future executes.


        For Sybase System 10 Users

Before Using the System 10 Driver
---------------------------------
Before using the Sybase System 10 driver, you must first
contact Sybase's Customer Service and Support line. Call (800)
879-2273 and request patch number EBF3284 for case number
198481.

Required Execute Access to TEMPDB
---------------------------------
To use Sybase System 10.0, users must have execute access to
TEMPDB.

Data Type Information
---------------------
The Sybase System 10.0 for Solaris installmaster script (on the server)
does not have the correct numeric and decimal data type information.
To get the correct data type information from the Sybase System 10 driver,
someone with the correct database permissions must execute the following
statements:

UPDATE sybsystemprocs.dbo.spt_datatype_info
    SET data_precision = 38, numeric_scale = 38
    WHERE type_name = 'decimal'
UPDATE sybsystemprocs.dbo.spt_datatype_info
    SET data_precision = 38, numeric_scale = 38
    WHERE type_name = 'numeric'
INSERT INTO sybsystemprocs.dbo.spt_datatype_info_ext values
    (26, 'precision,scale')
INSERT INTO sybsystemprocs.dbo.spt_datatype_info_ext values
    (10, 'precision,scale')


        For Text File Users

You cannot use single or double quotation marks as delimiters.


        For Users of Extend Products

If you are using Extend for Improv, Extend for Excel, or Extend for QPW
and you have set ExecAsync=1, you can obtain the same functionality
by setting the YieldProc attribute to 3.


        Aborting a Long-Running Query on a Flat File

INTERSOLV has included a nonstandard option to the flat-file drivers
that enables you to press the ESC key to abort a long-running query.
To use this option, create a separate data source for each application.
Open the ODBC.INI file, and, under the section for the data source
you created, add the line WorkArounds=32.



        Loading INFORMIX and NetWare SQL DLLs Correctly

The distribution diskette contains a utility called QEDLLOAD.EXE. If
you use the INFORMIX or NetWare SQL drivers, this utility tries to
load the following DLLs:

WXQLCALL.DLL, which is required for NetWare SQL
LDLLSQLW.DLL, which is required for INFORMIX.

To function, these files must be loaded into low memory (the first
640K). This can be a problem, because by the time you attempt to
load one of these DLLs, other files may occupy the available space
in low memory. When this happens, the DLL is loaded into available
high memory (above 1000K), where it does not function correctly,
preventing your application from connecting. To prevent this problem,
load these DLLs immediately when entering Windows, while lower memory
space may still be available. QEDLLOAD.EXE is provided to do this
for you.

To have QEDLLOAD properly load one of these DLLs, you must create
new items in the Startup program group in the Program Manager. If
you no longer have a Startup group, add one as follows:

1 In the Program Manager, open the File menu and choose New. The New
  Program Object dialog box appears.
2 In this dialog box, select the New Program Group option, and click
  OK. The Program Group Properties dialog box appears.
3 Supply the information for this new group. In the Description box,
  type Startup as the name of the new group. In the Group File box,
  type STARTUP.GRP. Click OK.

To add QEDLLOAD to the Startup group, follow these steps:

1 Select the Startup group.
2 In the Program Manager, open the File menu and choose New. The New
  Program Object dialog box appears.
3 In this dialog box, select the New Program Item option, and click
  OK. The Program Item Properties dialog box appears.
4 Supply the information for this new item. In the Description box,
  type QEDLLOAD. In the Command Line box, type the full path and file
  name for QEDLLOAD.EXE, then the name of the DLL that you want loaded
  (WXQLCALL.DLL for NetWare SQL, LDLLSQLW.DLL for INFORMIX). Click OK.

After you complete this procedure, QEDLLOAD attempts to load the
specified DLL into low memory every time you start Windows.

If, after you complete this procedure, you attempt to connect to a data
source and you receive either of the following messages, retry with
fewer programs loaded in memory.

For NetWare SQL, the message is:

Insufficient DOS memory for Windows Requestor Interface

For INFORMIX, the message is:

There is not enough memory available

For INFORMIX, this may still not work, as the INET version 4.10 tries to
allocate a buffer in low memory. Even though the application may be able
to load the DLL in low memory, there may not be enough low memory
available to allocate the buffer required for TSR-based products
(INET 4.10).

Failure trying to allocate this buffer can result in odd behavior.


        Solving Connection Problems with QEDLLMGR

INTERSOLV supplies a tool called QEDLLMGR, which is primarily for
INTERSOLV Technical Support use. QEDLLMGR is not a supported product
and is provided on an as-is, use-at-your-own-risk basis. This tool
lists the DLLs that are loaded in memory.

DLLs (dynamic link libraries) are the software components used by
the ODBC DriverManager to connect to your DBMS server from your
client workstation. The Q+E drivers are implemented as DLLs, and
they call other DLLs provided by your DBMS vendor for network access.
Unfortunately, the error messages generated by the Microsoft ODBC
Driver Manager do not identify which DLL is missing if it cannot
locate one or more of the required DLLs on your system.

QEDLLMGR is useful for determining which required DLL files are
missing when your application cannot connect to the specified
data source. Since the ODBC Driver Manager provides no indication
of the problem when it cannot load a DLL, simple problems such
as an inadequate DOS PATH specification can be hard to solve. When
QEDLLMGR cannot load a DLL, it reports which files it cannot find.

If your ODBC application cannot load a Q+E driver DLL:

1 Double-click the QEDLLMGR icon.
2 Enter the driver's fully qualified pathname (the DOS path/filename
  that appears after the "driver=" in the ODBC.INI entry for your data
  source) in the Load command from the File menu.
3 Click OK.

QEDLLMGR then displays a message for each required DLL that it cannot
find. Consult your DBMS vendor's documentation, your network administrator,
or your database administrator to locate the missing DLLs. If QEDLLMGR
identifies a Q+E driver as the missing component, perform the following
steps:

1 Check to make sure that you spelled the driver file name and path
  correctly.
2 Our drivers are installed in your Windows \SYSTEM directory unless
  you relocated them after the installation. If you did relocate them,
  be sure that the directory you installed them in is on your DOS $PATH.
3 If you cannot locate the correct Q+E driver on your system, reinstall
  Q+E from the original source disks.


        Compatibility with Third-Party Drivers

Microsoft Access Driver
-----------------------
To have the Query Builder display a list of the tables in an Access
database, add the following line to each Access data source defined in
the ODBC.INI file:

QeDatabaseIsA=2

Microsoft Text Driver
---------------------
To use Q+E with the Microsoft ODBC Text driver, add the following line
to that driver's data source specification in the ODBC.INI file:

QeDataDictExtensions=1

Lotus Notes Driver
------------------
To have the Query Builder recognize the "$" in column names, edit the
ODBC.INI file and add the following line to each Notes data source
defined in the ODBC.INI file:

QeColumnFirstChars="$"
QeColumnMiddleChars="$"

The Notes driver does not support reading data in binary. However, Q+E
reads fields larger that 255 bytes in binary. Therefore, when a field is
larger than 255 bytes, the following error message appears:

Driver not capable

To work around this, add the following line to each Notes data source
defined in the ODBC.INI file:

QeReadMemoChar=1

Microsoft SQLServer Driver
--------------------------
The Microsoft SQLServer driver places the owner name before the
qualifier and database name. This prevents Q+E from opening a given
table properly. To work around this, add the following line to each
SQLServer data source defined in the ODBC.INI file:

QeQualifierSyntax=2

Microsoft Oracle Driver
-----------------------
The Microsoft Oracle driver places the table qualifier at the end, which
prevents Q+E from opening the table. To ensure that tables are opened
properly, add the following line to each ORACLE data source defined in
the ODBC.INI file:

QeQualifierSyntax=1

End of QDREAD.ME file