Introduction

The project of picoSQL was born in 1995. It was an ODBC driver for COBOL indexed files. It consisted of a DLL written in C++ on Windows 3.1 operating system. In the beginning the main effort was made in order to obtain a good compatibity with existing front-end (mainly the MS-Access ©, MS-Query © and VisualBasic ©) and in order to see COBOL files as a normalized relational DB.

The obtained success concurs to develop ulteriorly the product, refining the query optimizer and implementing an extended SQL, to exclusion of the DDL (Data Description Language). A later version, called PicoDB, were devoloped on UNIX system in client/server architecture.

Installation

The installation is particularly simple: if you have the binary distribution, is sufficient to extract the compressed files in one directory (\ under Windows NT/2000/XP) and execute:

startTestDb.sh (Unix/Linux)

startTestDb.bat (Windows) 

iSQLViewerTest.sh (Unix/Linux)

iSQLViewerTest.bat (Windows)

picosql.sh (Unix/Linux)

picosql.bat (Windows)

The installation directory contains the following subdirectory:

• bin - where all the executables programs reside;
• bin - where all the libraries reside;
• inc - where all the header files reside;
• java - where all the Java programs and the JDBC driver reside;
• doc - where the documentation reside;

PicoSQL consists fundamentally in a program, picosqld, to activate through inetd (or xinetd) or picoserv. In such a way it becomes a net service binded to a port, that is to a entire number comprised between 1 and 65535; this number (as an example 6789) must always be specified on the command line of picosqld. As an example:

picosqld 6789

picoserv [-f] commandLine portNumber

picoserv "picosqld 6789" 6789

When picosqld receive a connection request, it reads a configuration file to find the necessary informations. This file is a text file on Unix/Linux systems and is the system registry file on Windows. In the latter case you can modify the configuration using the regedit program.

• Unix/Lunixthe file read for configuration is

  $HOME/.picosql.ini

  or, if this file is missing

  /etc/picosql.ini

  The file consists of sections and parameters. A section begins with the name of the section in square brackets and continues until the next section begins. Sections contain attributes of the form

  name=value

  The file is line-based - that is, each newline-terminated line represents either a comment, a section name or a parameter. Section and parameter names are not case sensitive. Only the first equals sign in a parameter is significant. Any line beginning with a semicolon (';') or a hash ('#') character is ignored, as are lines containing only whitespace. Each section corresponds to a database and comprises information like user, password and DB location. In the following example there are two database declared, the former called picoSqlTest, is accessible by anyone while the latter, called rubrica is accessible only by user pico giving the appropriate password.

  [picoSqlTest]
  DataDirectory=/home/test.db
  
  [rubrica]
  DataDirectory=/home/rubrica.db
  User=pico
  Password=soft
  PicoOdbcTrace=NO
  SuspensiveLock=YES
  ; for picosql client only
  server=localhost
  port=6789
   

• Windows NT/2000/XP On Windows system the configuration informations are read in the system registry file, starting on the key:

  HKEY_CURRENT_USER\Software\PicoSoft\PicoSQL

  or, if this key is missing:

  HKEY_LOCAL_MACHINE\Software\PicoSoft\PicoSQL

  Any key int this section correspond to a database. Under each key can be some string, each one corresponding to a database attribute, e.g. user, password and DB location. In the following example there are two database declared, the former called picoSqlTest, is accessible by anyone while the latter, called rubrica is accessible only by user pico giving the appropriate password.

   [HKEY_CURRENT_USER\Software\PicoSoft\PicoSQL\picoSqlTest]
   DataDirectory=C:\home\test.db
  
   [HKEY_CURRENT_USER\Software\PicoSoft\PicoSQL\rubrica]
   DataDirectory=C:\home\rubrica.db
   User=pico
   Password=soft
   PicoOdbcTrace=NO
   SuspensiveLock=YES
   server=localhost
   port=6789