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A relational and transactional database system

Users guide ( covers cego version 2.54.4 )
by Bjoern Lemke, 04.02.2026

Cego comes under the GNU Copyright
(C)opyright 2000-2026 by Bjoern Lemke

Cego implements a multithreaded, relational and transactional database system with support for a SQL query language and several client access interfaces.
Cego is easy to configure and easy to use. The database administrator is supported in a smart way to set up any database system in a few minutes.
Within one Cego database instance, several independent transaction spaces ( tablesets ) can reside. Tablesets enable the administrator to set up a cloud-ready database for dedicated users or customers. For the unpatient user, the section Getting Started describes an easy setup of a single node database configuration. To get in touch with the basics, single node configurations are described first without any distributed database aspects.
The Cego SQL language features are described the the section Cego SQL language . For the more advanced database programmer, the DBD Driver , the PHP cego extension , the JDBC Driver , the C API and C++ API could be interesting sections.

Table of Contents (TOC)

1	Overview
2	Getting Started
2.1	... Building up a tableset using cgmkdb
2.2	... Building up a tableset manually
2.3	... Using the first tableset
3	The database xml configuration
3.1	... General attributes
3.2	... User entries
3.3	... Role entries
3.4	... Scan date format entries
3.5	... Tableset entries
3.5.1	...... System files
3.5.2	...... Data files
3.5.3	...... Log files
3.5.4	...... Counters
4	Running the database
4.1	... cego - Database backend
4.1.1	...... Init mode
4.1.2	...... User setup mode
4.1.3	...... Role setup mode
4.1.4	...... Role permission setup mode
4.1.5	...... Tableset define mode
4.1.6	...... Tableset create mode
4.1.7	...... Tableset querycache setup mode
4.1.8	...... Tableset import/export mode
4.1.9	...... Batch mode
4.1.10	...... Daemon mode
4.1.11	...... Shift active logfile
4.1.12	...... General options
4.2	... cgclt - Console database client
4.2.1	...... Batch file processing
4.2.2	...... SQL dump file creation
4.2.3	...... Pager mode
4.2.4	...... Query abortion
4.2.5	...... Profile
4.3	... cgblow - Load simulation client
4.4	... cglog - Log reader
4.5	... Localization
4.6	... Logging
4.7	... Compatibility attributes
4.8	... Date format handling
4.9	... Tuning attributes
4.10	... Tableset init file
5	The Cego SQL language
5.1	... Fundamentals
5.1.1	...... Datatypes
5.1.2	...... Language Tokens
5.1.3	...... Base productions
5.2	... Creating a table
5.3	... Inserting into a table
5.4	... Attribute value handling
5.4.1	...... Integer and long values
5.4.2	...... String values
5.4.3	...... Boolean values
5.4.4	...... Datetime values
5.4.5	...... Arbitrary integer values
5.4.6	...... Float values
5.4.7	...... Double values
5.4.8	...... Decimal values
5.4.9	...... Small integer values
5.4.10	...... Tiny integer values
5.4.11	...... Lob values
5.4.12	...... Insert by select
5.4.13	...... Bulk insert
5.5	... Selecting from a table
5.5.1	...... Selection
5.5.2	...... Alias
5.5.3	...... Joins
5.5.4	...... Conditions
5.5.5	...... Distinct
5.5.6	...... Ordering
5.5.7	...... Grouping
5.5.8	...... Having
5.5.9	...... Nested Query
5.5.10	...... Inner Join
5.5.11	...... Outer Join
5.5.11.1	......... Left outer Join
5.5.11.2	......... Right outer Join
5.5.12	...... Union all
5.5.13	...... Numeric functions
5.5.14	...... String functions
5.5.14.1	......... Regmatch function
5.5.15	...... Date functions
5.5.16	...... Blob functions
5.5.17	...... Clob functions
5.5.18	...... Arithmetic functions
5.5.19	...... Case when clause
5.5.20	...... Execution plan
5.5.21	...... System tables
5.6	... Updating a table
5.7	... Deleting from a table
5.8	... Truncating a table
5.9	... Dropping a table
5.10	... Altering a table
5.11	... Using indexes
5.11.1	...... Index check
5.12	... Using foreign keys
5.13	... Using check constraints
5.14	... Using table aliases
5.15	... Views
5.16	... Procedures
5.16.1	...... Procedure sample 1 - Simple table copy
5.16.2	...... Procedure sample 2 - Insert with id counter
5.16.3	...... Procedure sample 3 - Exception Handling
5.17	... Trigger
5.18	... Counter
5.18.1	...... Adding a counter
5.18.2	...... Listing counters
5.18.3	...... Using a counter
5.18.4	...... Geting the current value of a counter
5.18.5	...... Setting a counter
5.18.6	...... Dropping a counter
5.19	... Tableset information commands
5.19.1	...... uptime
5.19.2	...... show
5.19.3	...... list
5.19.4	...... tableinfo
5.19.5	...... tablesize
5.19.6	...... tupleinfo
5.19.7	...... desc
5.19.8	...... sync
5.20	... Reorganisation
5.21	... Append mode
5.22	... Grace mode
5.23	... BTree Cache
5.23.1	...... BTree Cache Performance
5.24	... Table locking
6	Transactions
6.1	... Starting a transaction
6.2	... Committing a transaction
6.3	... Aborting a transaction
6.4	... Autocommit
6.5	... Isolation level
7	Database administration with cgadm
7.1	... Connecting to the database
7.2	... Retrieving database information
7.2.1	...... Database parameter information
7.2.2	...... Pool information
7.2.3	...... Lock information
7.2.4	...... Thread administration
7.3	... User administration
7.3.1	...... Role management
7.3.2	...... User management
7.4	... Retrieving tableset information
7.4.1	...... Datafile information
7.4.2	...... Online Redo Log information
7.4.3	...... Archive Log information
7.4.4	...... Transaction information
7.5	... Realtime monitor
7.6	... Basic tableset administration
7.6.1	...... Defintion
7.6.2	...... Creation
7.6.3	...... Start and stop
7.6.4	...... Drop
7.6.5	...... Remove
7.6.6	...... Datafile expansion
7.6.7	...... Tableset verification
7.6.8	...... Tableset correction
7.6.9	...... Checkpoint setting
7.6.10	...... Auto correction
7.6.11	...... Checkpoint Dump
7.7	... Caching
7.7.1	...... Query Cache
7.7.2	...... Table Caching
7.8	... Backup administration
7.8.1	...... Import and export
7.8.2	...... Archive log mode
7.8.3	...... Online backup mode
7.8.4	...... Tableset recovery
8	Backup and Recovery
8.1	... Export and Import
8.2	... Advanced methods
8.2.1	...... Offline backup
8.2.2	...... Online backup
8.2.2.1	......... External backup
8.2.2.2	......... Internal backup
8.2.3	...... Backup statistics
8.2.4	...... Backup branches
8.2.5	...... Recovery procedures
8.2.5.1	......... Up to crash recovery
8.2.5.2	......... Point in time recovery
8.2.5.3	......... From scratch recovery
8.2.5.4	......... Online Log Rescue
8.2.6	...... Logmanager execution shell
8.2.7	...... Log tracing with cglog
8.3	... Shadow Database
9	Using the DBD Driver
9.1	... DBD connection string
9.2	... Executing statements immediately
9.3	... Executing prepared statements
9.4	... Fetching data
10	Using the JDBC Driver
10.1	... Loading the JDBC driver
10.2	... JDBC connection string
10.3	... Using statements
10.4	... Using prepared statements
10.5	... Using callable statements
11	Using the CegoNet C++ API
11.1	... Connecting to the database
11.2	... Executing a query
11.3	... Fetching data
11.4	... Retrieving query results
11.5	... Class Reference
11.5.1	...... CegoNet
11.5.2	...... CegoField
11.5.3	...... CegoFieldValue
11.5.4	...... CegoProcVar
12	Using the CegoAdmNet C++ API
12.1	... Connecting to the database
12.2	... Administration methods
13	Using the C Wrapper API
13.1	... Connecting to the database
13.2	... Executing a query
13.3	... Tuple fetching
13.4	... Prepared Statements
13.5	... Function Reference
14	Using the PHP extension
14.1	... Connecting to the database
14.2	... Preparing a query
14.3	... Executing a query
14.4	... Tuple fetching
14.5	... Parameter binding
14.6	... Function Reference
15	Cego Bridge
15.1	... Import
15.2	... Export
16	Database Tuning
16.1	... Incompiled parameters
16.2	... Configuration parameters