About Concordance Desktop database files

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About Concordance Desktop database files

When you create a database, you import the initial load files to populate the database with records. These initial files can be either PST files, electronic documents, or delimited text files prepared by a vendor (or other party), and can be imported as you create the new Concordance Desktop database. Concordance Desktop provides a Creation Wizard to help you create and import the documents all together.

You can import the following types of files:

Delimited text file

Native files

Electronic documents

E-mails and attachments


Concordance Desktop databases

Each Concordance Desktop database uses several files during operation. Only four are absolutely required to open and use a database. The four mandatory files are the database control block (.dcb), the numeric, date, and text file (.ndx), the text file (.txt), and the user management file (.sec). All of the other files can be recreated without damaging the integrity of the data. At a minimum, these four files should be backed up for archival purposes.

For more information see backing up databases.

A B-tree file uses a tree data structure to provide fast search results. The tree data structure minimizes the number of times the database is accessed when searching for a record, resulting in faster searches.

The .TRK file in Concordance Desktop uses SQLite. SQLite is an embedded relational database engine, which brings more stability to the functions of the .TRK file. Because SQLite is an embedded database, SQLite does not increase the required maintenance and administration of Concordance Desktop.

Concordance Database Files


File Description


File Type



Stores a list of concatenated databases

Text file



Stores association between media keys and native and image files including markup history

SQLite file


CPL script

Store Concordance Desktop Programming Language (CPL) scripts

Script file


CPL script

Stores compiled versions of CPL script

Script file


User management

Stores field and menu access for all users (when exported by user)

Text file


Delimited text

Contains metadata and sometimes OCR for document records

Text file


Data control block

Database definition, including fields, document count, and other settings




All unique words in the database, in alphabetical order

This is not a plain text file, it cannot be read or edited by a text editor or word processor

B-tree file


Print settings

Saves print settings for reports generated using the standard print feature

User generated file



Concordance Desktop Concordance Desktop server database

A link file that opens a database on a remote Concordance Desktop server

Text file


Fuzzy search dictionary

The fuzzy search dictionary contains homonyms for words in the search dictionary

This file is created and updated by indexing and reindexing

B-tree file


Back Up

A tag backup file that stores tagging information. Generated by running the TagSaver.cpl



Configuration settings

Stores various configuration settings

Text file


Inverted text

Used with the dictionary during searches



Key fields

Field storage for fast relational searching

B-tree file


Table layout

Stores the defined table layouts

B-tree file


Sorting layout

Stores the defined sorting layouts for the current database



Editing layout

Stores the defined editing layouts for the current database



Word lists

Contains predefined values that can be selected from a list when editing fields

When a list is assigned to a specific field, it's called an Authority List

B-tree file


Numeric, date, and text fields

Stores data for the fixed length field types: Numeric, Date, and Text



Print settings

A Concordance Desktop Image print file that stores print settings for print jobs generated by Concordance Desktop Image (Opticon)

User generated




Stores search query strings



User management control

Stores user management settings

B-tree file



Stores search history and auto-restore settings




Contains the noise words that are ignored during database indexing

B-tree file



Stores the user defined synonyms

B-tree file



Full text paragraph field storage

Text file


Transaction tracking

Relational SQLite file structure that stores tags and tag histories, security (field and menu access for all users) and replication data

SQLite file



Stores the current state of markups and placeholders


Temporary Files

Concordance Desktop creates and uses temporary files, which are automatically erased when you leave the program. However, temporary files are not erased if there is a power outage or other problem which causes an irregular program termination. Concordance Desktop places the files in the system's temporary directory as defined by the Windows TEMP environment variable. The two most common functions that create temporary files are indexing and reindexing.

When indexing a database, two temporary files are saved in the local computer's temp directory. Both files begin with the prefix C- and end with the .tmp extension. These files represent the temporary .dct and .ivt files. They are not initially saved on the network server since network latency would severely decrease performance. When indexing is complete, the resulting .dct and .ivt files are copied to the Concordance Desktop server.

When reindexing a database, the same temporary files are saved in the local computer's temp directory. In addition, a temporary dictionary file with a .dcb file extension is saved in the local computer's database directory. This file contains information from the newly created records. Near the end of the reindexing process, this dictionary file is merged with the main dictionary file on the network server.

For more information about indexing and reindexing, see Indexing Databases.