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If you use Eclipse Ganymede with large projects on linux you may run out of memory. To prevent this happening, you can specify the amount of memory to be allocated to Eclipse in the eclipse.ini file which is located in the eclipse directory.

Specifying this seems to reslove the problem:

-Xmx512m
-XX:MaxPermSize=512m

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In this article Barry Mavin, CEO and Chief Software Architect for Recital, details Working with Stored Procedures in the Recital Database Server.

Overview

Stored procedures and user-defined functions are collections of SQL statements and optional control-of-flow statements written in the Recital 4GL (compatible with VFP) stored under a name and saved in a Database. Both stored procedures and user-defined functions are just-in-time compiled by the Recital database engine. Using the Database Administrator in Recital Enterprise Studio, you can easily create, view, modify, and test Stored Procedures, Triggers, and user-defined functions

Creating and Editing Stored Procedures

To create a new Stored Procedure,  right-click the Procedures node in the Databases tree of the Project Explorer and choose Create. To modify an existing stored procedure select the Stored Procedure in the Databases Tree in the Project Explorer by double-clicking on it or selecting Modify from the context menu . By convertion we recommend that you name your Stored Procedures beginning with "sp_xxx_", user-defined functions with "f_xxx_", and Triggers with "dt_xxx_", where xxx is the name of the table that they are associated with.

Testing the Procedure

To test run the Stored Procedure, select the Stored Procedure in the Databases Tree in the Project Explorer by double-clicking on it. Once the Database Administrator is displayed, click the Run button to run the procedure.

Getting return values

Example Stored Procedure called "sp_myproc":
parameter arg1, arg2
return arg1 + arg2
Example calling the Stored Procedure from C# .NET:
////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;

////////////////////////////////////////////////////////////////////////
// sample code to call a Stored Procedure that adds to numeric values together
public int CallStoredProcedure()
{
	RecitalConnection conn = new 
		RecitalConnection("Data Source=localhost;Database=southwind;uid=?;pwd=?");
	RecitalCommand cmd = new RecitalCommand();
	cmd.Connection = conn;
	cmd.CommandText = "sp_myproc(@arg1, @arg2)";
	cmd.CommandType = CommandType.StoredProcedure;
	cmd.Parameters["@arg1"].Value = 10;
	cmd.Parameters["@arg2"].Value = 20;
	conn.Open();
	cmd.ExecuteNonQuery();
	int result = (int)(cmd.Parameters["retvalue"].Value);    // get the return value from the sp
	conn.Close();
	return result;
	}

Writing Stored Procedures that return a Resultset

If you want to write a Stored Procedure that returns a ResultSet, you use the SETRESULTSET() function of the 4GL. Using the Universal .NET Data Provider, you can then execute the 4GL Stored Procedure and return the ResultSet to the client application for processing. ResultSets that are returned from Stored Procedures are read-only.

Example Stored Procedure called "sp_myproc":
parameter query
select * from customers &query into cursor "mydata"
return setresultset("mydata")
Example calling the Stored Procedure from C# .NET:
////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;

////////////////////////////////////////////////////////////////////////
// sample code to call a stored procedure that returns a ResultSet
public void CallStoredProcedure()
{
	RecitalConnection conn = new 
		RecitalConnection("Data Source=localhost;Database=southwind;uid=?;pwd=?");
	RecitalCommand cmd = new RecitalCommand();
	cmd.Connection = conn;
	cmd.CommandText = "sp_myproc(@query)";
	cmd.CommandType = CommandType.StoredProcedure;
	cmd.Parameters["@query"].Value = "where not deleted()";
	conn.Open();
	RecitalDataReader dreader = cmd.ExecuteReader();
	int sqlcnt = (int)(cmd.Parameters["sqlcnt"].Value);    // returns number of affected rows
	while (dreader.Read())
	{
		// read and process the data
	}
	dreader.Close();
	conn.Close();
}
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In this article Barry Mavin, CEO and Chief Software Architect for Recital, gives details on Working with user-defined Functions in the Recital Database Server.

Overview

User-defined functions (UDFs) are collections of statements written in the Recital 4GL (compatible with Visual FoxPro) stored under a name and saved in a Database. User-defined functions are just-in-time compiled by the Recital database engine. User-defined functions can be used in SQL statements to extend the power and flexibility of the inbuilt functions. Using the Database Administrator in Recital Enterprise Studio, you can easily create, view, modify, and test Stored Procedures, Triggers, and user-defined functions.

Tip
You can also extend the Recital Database Server with C Extension Libraries and use the functions defined within that library also.

Creating and Editing user-defined functions

To create a new User-defined function,  right-click the Procedures node in the Databases tree of the Project Explorer and choose Create. To modify an existing User-defined function select the User-defined function in the Databases Tree in the Project Explorer by double-clicking on it or selecting Modify from the context menu. By convertion we recommend that you name your User-defined functions beginning with "f_xxx_", where xxx is the name of the table that they are associated with.

Testing the user-defined function

To test run the user-defined function, select it in the Databases Tree in the Project Explorer by double-clicking on it. Once the Database Administrator is displayed, click the Run button to run it.

Example

Example: user-defined function "f_order_details_total".
////////////////////////////////////////////////////////////////////////
// example user-defined function
function f_order_details_total(pUnitprice, pQuantity, pDiscount)
    return (pUnitprice + pQuantity + pDiscount) > 0
endfunc
Example: using the user-defined function in a SQL SELECT statement.
////////////////////////////////////////////////////////////////////////
// sample code to use a user-defined function in a SQL SELECT statement
select * from customers where f_order_details_total(Unitprice, Quantity, Discount)

Using user-defined function libraries with the Recital Database Server

You can place all of the user-defined functions associated with a particular table into a procedure library. You then define an Open Trigger for the table that opens up the procedure library whenever the table is accessed. This is a much faster way of using user-defined functions as it reduces the amount of file open/close operations during a query and also simplifies development and maintenance.

By convertion we recommend that you should name the library using the convention "lib_xxx", where xxx is the name of the table that the library is associated with.

Example: procedure library in lib_order_details.
////////////////////////////////////////////////////////////////////////
// example user-defined functions
function f_order_details_total(pUnitprice, pQuantity, pDiscount)
    return (pUnitprice * pQuantity - pDiscount) > 0
endfunc

function f_order_details_diff(pUnitprice, pQuantity, pDiscount, pValue)
    return f_order_details_total(pUnitprice, pQuantity, pDiscount) - pValue
endfunc
Example: Open Trigger in dt_order_details_open.
////////////////////////////////////////////////////////////////////////
// This trigger will open up the procedure library when the table is opened
set procedure to lib_order_details additive
Example: Close Trigger in dt_order_details_close.
////////////////////////////////////////////////////////////////////////
// This trigger will close the procedure library when the table is closed
close procedure lib_order_details
Example: using the user-defined function in a SQL SELECT statement.
////////////////////////////////////////////////////////////////////////
// sample code to use a user-defined function in a SQL SELECT statement
select * from customers where f_order_details_total(Unitprice, Quantity, Discount)

User-defined functions can also be used with any of the Client Drivers that work with the Recital Database Server.

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Subclipse is an Eclipse Team Provider plug-in providing support for Subversion within the Eclipse IDE. This plugin is required in order to use the recital eclipse workspace.
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This useful  firefox plugin lets you integrate sugarcrm and gmail.


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TIP
If you are using the Oracle Gateway in Recital, make sure the Oracle environment (ORACLE_HOME, ORACLE_SID etc.) is set up before starting the Recital Server.  If not, you will see the error ORA-01019.  A call to the Oracle environment setup script can be added to the /etc/init.d/recital script if your Recital Server is set to run on startup.
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Recital 10 introduced the DIE( )and EXIT( ) functions. These functions operates in the same way as the PHP DIE( ) and EXIT( ) functions. They output a message and terminate the current session in both Recital and Recital Web.
try
  open database southwind
catch
  die("Cannot open database, please try later.")
endtry
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This article looks at After Image Journaling and audit trails in Recital using SET JOURNAL and associated commands.

Overview

After Image Journaling, used in conjunction with a structured backup policy is an effective disaster recovery solution. Any transaction that takes place on a table that is being journaled is logged in the journal file. In the event of a disk crash or similar event in which the table is lost, the journaled transactions can be reapplied to the latest backup copy of the table. Alternatively or additionally, the journal can be used to provide an audit trail to all modifications made to the table data.

NOTE: Recital also provides Before Image Journaling via BEGIN TRANSACTION / END TRANSACTION blocks, allowing unsuccessful transactions to be rolled back to a set saved state.

SET JOURNAL and RECOVER

Regular backups are an essential routine for any system, but in high-transaction environments restoration of the latest backup can still mean a major loss of data. After image journaling can successfully be used as part of your disaster recovery strategy to minimize data loss and down time. Recital after image journaling functionality is based on the use of the SET JOURNAL and RECOVER commands.

SET JOURNAL
SET JOURNAL TO [<.dbj filename> | ()]
SET JOURNAL ON | OFF | ()

The SET JOURNAL command is used to enable the After Image Journaling and audit trail for the active table. The TO <.dbj filename> clause associates the specified transaction journal file with the active table.  If the journal file does not exist, it will be created.  The filename can be substituted with a <expC>, enclosed in round brackets, which returns a valid filename.  If no file extension is specified, ‘.dbj’ is used. When specifying a journal file, it is recommended that the journal file is stored on a different disk than that which the table is stored on, so that if a fatal disk error occurs, then the journal file will not be lost along with the table. 

//Enable journaling for the southwind!orders table
open database southwind
use orders
set journal to /journals/ord_journ

The <.dbj filename> is a standard table.  It contains seven fields that are specific to a journal file, followed by the first 249 fields of the associated table.

The first seven fields in the journal are:


Field

Type

Display

Storage

Description

AUD_DATE

Date

8 | 10 *

4

The date on which the transaction was performed.

AUD_TIME

Character

8

8

 The time at which the transaction was performed, in the format HH:MM:SS.

AUD_TERM

Character

12

12

The name of the terminal from which the transaction was performed

AUD_UID

Short

5

2

The ID of the user who performed the transaction.

AUD_GID

Short

5

2

The group ID of the user who performed the transaction.

AUD_CMD

Short

4

2

The command number of the transaction performed from the command table below

AUD_RECNO

Integer

7

4

The record number in the associated table which the transaction was performed on.


* Dependent on SET CENTURY setting.

The AUD_CMD Command Reference Numbers are as follows:


Command

Number

DELETE

14

RECALL

36

REPLACE

41

BROWSE

6

CHANGE

8

EDIT

17

INSERT

26

APPEND

5

READ

35


Since journal files are standard Recital tables, you can use standard Recital commands such as the REPORT command to print audit trails, transaction logs, etc.

//Enable journaling for the southwind!orders table
open database southwind
use orders
set journal to /journals/ord_journ
//.. transactions
close data
//View journaled records
use /journals/ord_journ.dbj

Click image to display full size

Fig 1: Journal Record Example.

The SET JOURNAL TO command without a <.dbj filename> specified closes the active journal file and no further journaling will take place on the active table until the SET JOURNAL TO <.dbj filename> is reissued.

The journaling features are mainly used with shared tables.  It should be noted that there is an overhead in enabling transaction journaling, as records updated in a table are also written to the journal file. When records are appended into a journal file, locking is automatically performed so that multiple users can update the journal concurrently.  The associated table must be opened shareable for this to occur.  Each table can have a journal file associated with it. 

The SET JOURNAL ON | OFF command enables or disables transaction journaling.  This command is primarily used in applications where journaling can be disabled for a certain class of operations. By default, SET JOURNAL is ON, but no journal files are set.

NOTE: Only the first 249 fields of a table can be journaled: subsequent fields are ignored. The maximum number of fields in a Recital table is 256.

RECOVER
RECOVER FROM <.dbj filename> | ()

The RECOVER command uses the journal file to reapply lost transactions to a previous backup of the data after a fatal error such as a disk head crash. The FROM clause specifies the journal file to use. The file name can be substituted with an <expC>, enclosed in round brackets, which returns a valid filename.  If no file extension is specified, then ‘.dbj’ is assumed. 

Regular backups are essential to the successful use of After Image Journaling.   It is also very important to reinitialize the journal file after each backup: either open the journal file as you would a normal table and use the ZAP command, or delete the file completely. If a fatal error occurs, such as a disk head crash, the table and index files must be restored from a backup, then the RECOVER command executed. RECOVER will reapply' all of the transactions in the journal file to the table, and update the indexes.  After the RECOVER command has completed, you can continue with normal processing. 

//Create a backup of the southwind!orders table
//...backup table and associated files
//Reinitialize the journal file
erase /journals/ord_journ.dbj
//Enable journaling for the southwind!orders table
open database southwind
use orders
set journal to /journals/ord_journ
//.. transactions
//Restore the backup of the southwind!orders table
//...restore
//Open the restored backup
open database southwind
use orders
//Reapply the transactions using the journal
recover from /journals/ord_journ.dbj
//Now, enable the journal file again or
//restart with a new backup

Journaling Memo Fields

By default, memo fields - variable length text fields - are not journaled due to the possible storage overhead of multiple copies of potentially large blocks of text. But, if memo journaling is required, the SET MEMOJOURNAL ON command can be used to enable this.

SET MEMOJOURNAL
SET MEMOJOURNAL ON | OFF | ()

The SET MEMOJOURNAL command causes memo fields to be journaled when journaling is set on a table. This command allows the optional logical expression <expL> to be evaluated.  If a value of  .T. is returned, MEMOJOURNAL is set ON.  If a value of .F. is returned, MEMOJOURNAL is set OFF.  By default SET MEMOJOURNAL is OFF.

Like a normal Recital table, the journal holds only a pointer to a data block in an associated memo file, not the actual memo data itself. The journal's memo file has a file extension of .dbm rather than the standard Recital .dbt. Therefore, if the journal is being opened as a table, in order to view the journal's memo data, the SET MEMOEXT command should be used.

//Enable journaling for the southwind!suppliers table
open database southwind
use suppliers
set journal to /journals/sup_journ
//.. transactions
close data
//Set filename extension for memo file
set memoext to '.dbm'
//View journaled records
use /journals/sup_journ.dbj

Summary

The After Image Journaling enabled by the SET JOURNAL and RECOVER commands can be used in conjunction with a strict backup regime to minimize data loss in cases where tables become damaged or irretrievable. Journal files can be accessed like standard Recital tables and provide detailed information about the transactions applied to a table, so can be used for auditing purposes.

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Recital 10 enhances the SQL optimizer. Now, production indexes with a FOR <conditions> will be used to optimize SQL SELECT statements. If a WHERE <condition> on a SELECT statement matches a FOR <condition> on an index tag, this index will be used to optimize the query. The WHERE <condition> must be an exact match with the  FOR <condition>.  For example;
USE accounts 
INDEX on account_no TAG outstanding FOR balance  > 0
EXPLAIN SELECT * FROM accounts WHERE balance  > 0
  Optimized using for condition on tag 'OUTSTANDING'
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Subclipse is an Eclipse Team Provider plug-in providing support for Subversion within the Eclipse IDE. This plugin is required in order to use the recital eclipse workspace.
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