 | Advanced Operations Guide (v10) |  |
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The client configuration options are available in all the different installation setups. These options must be configured separately for each workstation, which includes servers acting as workstations.
You can configure the client using the graphical utility Pervasive PSQL Control Center or the command-line interface utility bcfg. For PCC, see Using Pervasive PSQL Control Center in Pervasive PSQL User's Guide. For bcfg, see Configuration Through CLI Utility .
The following table is a mapping of all the available client configuration options and their settings.
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Configuration Option
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Parameter Name
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Cache Engine
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The settings available under Cache Engine Debugging perform the same functions for the client cache as similar settings under Server. See the related server settings for Debugging .
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Access contains the following configuration settings:
This option specifies whether the MicroKernel Router should store in the registry a list of computers that do not have Pervasive PSQL running on them. This decreases the time it takes to find a gateway engine. You must set this option to Off when new engines are added to the workgroup.
This setting specifies the number of times the MicroKernel Router attempts to connect to the target engine.
This setting is primarily for use with legacy applications that used Pervasive PSQL (IDS). IDS functionality is now integrated into the core product and IDS is no longer available as separately installed components. The integration of IDS requires that you reconfigure your client/server environment.
Typically, an application provides its own file location information. As an alternative, IDS provided file location mapping based on information in a text file, idshosts.
If your applications do not use the mapping feature through idshosts, set Use IDS to Off to improve performance.
If your applications already use idshosts, or if you prefer to use this alternative method to map file locations, set Use IDS to On. See Using the idshosts File .
Note
Pervasive PSQL 8.5 or later is required if you set Use IDS to On or if your legacy applications pass file location information in the format of a PIDS URL. The requester uses database URIs to represent the IDS information. Database URIs were added with Pervasive PSQL 8.5. See in Pervasive PSQL Programmer's Guide, which is part of the Pervasive PSQL software development kit (SDK).
This setting determines whether a local application tries to connect to a local engine. If set to Off, no attempt is made to connect to a local engine.
This setting specifies whether the MicroKernel Router allows access to a Server or Workgroup engine running on a remote server. If this value is set to On, and Use Local MicroKernel Engine is set to On, the remote server is tried first.
Prior to Pervasive.SQL 2000i (Service Pack 3), this setting was named "Requester."
We recommend you keep Use Remote MicroKernel Engine set to On for a Microsoft's File and Print Services for NetWare (FPNW) server running Pervasive PSQL. You may receive a Status Code 94, "The application encountered a permission error," if you change this setting to Off when you are running the Btrieve Interface locally on the FPNW server and using a local FPNW drive mapping or local FPNW UNC path.
See Wire Encryption .
See Wire Encryption Level .
These settings apply only when the cache engine is running. The Workgroup engine doubles as a cache engine. Note, however, that the cache engine is not used if a database server engine is running.
Cache Engine contains the following configuration settings:
This setting instructs the cache engine to allocate resources, including threads and memory buffers, when the cache engine is started.
If you turn this option off, the cache engine does not allocate any resources until the first operation request. Pervasive PSQL components automatically allocate resources as needed. Therefore, in most cases you do not need to do so explicitly.
This setting displays only if the Workgroup engine is running.
This setting causes the cache engine to free considerable memory and thread resources to the system and return to a minimal state after a certain amount of time without any active clients. The time interval is specified by the value of Minimal State Delay. The cache engine reallocates resources when another client becomes active.
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Name
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Type
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Range
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Default
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Units
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Cache Allocation Size
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Numeric
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65536 bytes to the amount limited by memory
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Initialized dynamically at first start-up
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bytes or megabytes
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This setting specifies the size of the Level 1 cache (in bytes) that the MicroKernel allocates; the MicroKernel uses this cache when accessing any data files. The MicroKernel uses values that are multiples of 16 KB or 16,384 bytes. If you specify a number that is not a multiple of 16 KB, the MicroKernel rounds that number down to the nearest multiple of 16 KB and allocates the cache to exactly that size.
The value required and returned for the cache allocation size varies depending on the combination of Pervasive PSQL server and clients. See Table Cache Allocation Size Value By Product Version .
Speaking very generally, overall performance is usually best when the Cache Allocation Size is a value less than 40% of the physical memory on the system, and the Configuration setting Max cache engine Memory Usage is set to a value greater than 40%. Your exact optimal settings will depend on the size of your data files, the number of other applications running on the system, and the amount of memory installed in the computer.
The database engine initially sets this value the very first time it starts up, and it writes the value to the Registry. The value is set to 20% of physical memory, up to a maximum of 64 MB. After the Registry setting is initialized, whenever the engine starts up, it reads the value from the Registry. The engine never re-calculates the setting. Changing the value using Configuration updates the value in the Registry. If you add or remove memory from the system, you must modify this setting manually to take best advantage of the new amount of memory available.
This setting specifies the maximum proportion of total physical memory that the cache engine is allowed to consume. L1, L2, and all miscellaneous memory usage by the cache engine are included. The database engine uses less if the specified proportion is not needed or not available.
If the value zero (0) is specified, then dynamic caching is turned off. In this case, the only cache available is L1, the size of which is specified by Cache Allocation Size.
For more information on tuning performance, please see Tuning Performance .
This setting displays only if the Workgroup engine is running.
This setting specifies how long the cache engine waits during a period of inactivity before returning to a minimal state. (This is the initial state in which the cache engine begins.) By returning to a minimal state, the cache engine frees considerable memory and thread resources to the system. In some cases, you may not want the cache engine to return to a minimal state. For example, you may be running a batch file that uses the cache engine repeatedly. The cache engine reallocates resources when another client becomes active.
This setting is ignored if the value of Back to Minimal State if Inactive is set to Off (the default).
These settings apply only when the cache engine is running. The Workgroup engine doubles as a cache engine. Note, however, that the cache engine is not used if a database server engine is running.
The settings available under Cache Engine Debugging perform the same functions for the client cache as similar settings under Server Debugging perform for the main database engine. For more information about each setting, see the related server setting:
Communication Protocols contains the following configuration settings:
This setting specifies whether you want the client to attempt to auto-reconnect during a network outage. A setting of On means Auto Reconnect is enabled.
Auto Reconnect is not in effect unless this setting is also enabled in the server configuration.
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Name
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Type
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Range
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Default
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Units
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Supported Protocols
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Multiple select
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(see below)
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(all 3 options below)
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none
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This setting specifies the protocols that are used by the client. If more than one protocol is specified, the client attempts to connect using all available protocols. When the first protocol succeeds, that protocol is used for the remainder of the session. The available options are:
You must have at least one protocol enabled at both the client and the server or they cannot communicate. NetBIOS is valid only for Pervasive PSQL Workgroup, not Pervasive PSQL Server. TCP/IP is the only supported protocol for Pervasive PSQL running on a Linux platform. Therefore, the Supported Protocols setting is not available on Linux.
The value of this setting specifies how long the client waits while searching for or connecting to a remote database engine. If this value is set too low, the client may return spurious "server not found" errors, because it is timing out before it has a chance to complete the connection. If the value is set too high, when the client attempts to connect to a server that is not reachable, you may encounter lengthy delays before receiving an error. Generally speaking, a value between 15 and 30 seconds is adequate for most networks. If you receive many "server not found" errors, try a higher setting.
This setting was previously named: TCP/IP Timeout for Communication Requester.
Performance Tuning contains the following configuration setting:
This setting specifies whether the client cache should be used. If this setting is Off, then the client caches single records in a relatively small fixed-size cache on the client workstation. If this setting is On, then the client uses the Cache Engine, if it is loaded in memory. If the Cache Engine is not loaded, this setting has no effect.
The client cache is similar in many ways to the Workgroup engine. By default, it auto-loads into memory when an application first accesses the database, and it unloads a few minutes after that application is stopped.
You may wish to keep the client cache in memory at all times to avoid the performance cost of re-populating the cache with each usage session. If you want to keep the client cache loaded, run the following command from a command prompt: file_path\PSQL\bin\w3dbsmgr -btrv.
For default locations of Pervasive PSQL files, see Where are the Pervasive PSQL v10 files installed? in Getting Started With Pervasive PSQL.
After the Cache Engine starts, a tray icon appears, allowing you to control the client cache from the Windows task bar. To stop the client cache, right-click on the client cache tray icon then click Stop Engines and Exit.
Pervasive PSQL keeps the client cache fully synchronized with the database engine cache and other client cache locations. This behavior is entirely transparent, meaning that you should never need to worry about what records are or are not in any given client cache.
The following operations are not stored in the client cache:
Security contains the following configuration setting:
This setting controls runtime server support. If enabled with the value Yes, the current user name and password for the drive on which you are presently running are used. To enable RTSS with a different username, enter "user_name,password".
Note that you may use a fully qualified NDS user name in the format CN=user_name.O=organization,password. The user name may also be a simple Bindery name. The first entry in the Bindery context list must contain the simple name or the NDS login fails. If the NDS login fails for a simple name, a Bindery login is attempted. The Bindery login may cause delays while the login attempt is processing.
SUPERVISOR and ADMIN are not valid user names, even if supplied with the correct password. If the requester cannot find a login user name other than SUPERVISOR or ADMIN, it does not attempt to login.
Application Characteristics contains the following configuration settings:
This option instructs the transactional interface to allow embedded spaces in file names for transactional interface operations.
This setting controls whether or not the transactional interface splash screen displays. The splash screen displays the first time a client requester loads.
This option can be used for legacy Btrieve applications to prevent the requester from verifying that the index key length passed to the client requester is large enough to hold the key. Setting this option to "off" may allow such applications to avoid status 21 errors.
Caution
If set to "off," this option disables the check by the Pervasive requester to prevent memory overwrites. A memory overwrite can cause a general protection fault (GPF) among other undesirable conditions.
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