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String types

Section

Description

CHAR

CHAR is a FairCom database field type containing a fxed-length, padded string value.

VARCHAR

VARCHAR is a FairCom database field type containing a variable-length string.

LVARCHAR

LVARCHAR is a FairCom database field type containing a variable-length string.

CHAR

CHAR is a FairCom database field type containing a fixed length, padded string value, such as "my string". It is stored in a record as a series of UTF-8 characters. It has a fixed length between 1 and 65,500 bytes, which is stored once in the table's header. If a value is smaller than its fixed length, the server uses padding to fill in missing bytes at the end.

Because CHAR is a fixed-length string, storing a string smaller than the specified field length causes the server to modify the string value by padding the string up to the full length of the field. By default, the server pads the string with the NULL character 0x00 or the byte value specified in the "padValue" property.

CHAR's behavior in different APIs:

  • In FairCom's JSON DB API, SQL, and CTDB APIs, a CHAR value is represented as a string.

    The string includes characters up to but not including the first NULL 0x00 character. This makes a fixed-length string appear to work the same as a variable-length string, but when stored in the FairCom database, a CHAR field is padded so that it occupies the user-defined fixed-length of the field.

  • In FairCom's ISAM and CTDB APIs, an LVARCHAR value is submitted and returned as a sequence of UTF-8 characters.

VARCHAR

VARCHAR is a FairCom database field type containing a variable-length string, such as "my string". It is stored in a record as a variable-length sequence of UTF-8 characters with a user-specified maximum length of up to 65,500 bytes.

VARCHAR's behavior in different APIs:

  • In FairCom's JSON DB API, a VARCHAR value is represented as a JSON string.

  • In FairCom's SQL API, a VARCHAR value is submitted and returned as a string — for example, 'hello'.

  • In FairCom's ISAM and CTDB APIs, a VARCHAR value is submitted and returned as a sequence of UTF-8 characters.

LVARCHAR

LVARCHAR is a FairCom database field type containing a variable-length string, such as "my string". It is stored as a variable-length sequence of bytes up to 2 gigabytes in length. Each LVARCHAR field in each record includes a 4-byte length header. The bytes are interpreted as UTF-8 encoded characters.

LVARCHAR's behavior in different APIs:

  • In FairCom's JSON DB API, an LVARCHAR value is represented as a JSON string.

  • In FairCom's SQL API, an LVARCHAR value is submitted and returned as a string — for example, 'hello'.

  • In FairCom's ISAM and CTDB APIs, an LVARCHAR value is submitted and returned as a sequence of UTF-8 characters.

CHAR is a FairCom database field type containing a fxed-length, padded string value, such as "my string". It is stored in a record as a series of UTF-8 characters. It has a fixed-length between 1 and 65,500 bytes, which is stored once in the table's header. If a value is smaller than its fixed length, the server uses padding to fill in missing bytes at the end.

A record contains data about one thing. A record describes the attributes of a thing using one or more fields. Zero or more records exist in a table; thus, a table contains data about zero or more things.

Different systems represent records differently. A JSON database represents each record as a JSON document. SQL represents each record as a row containing one or more columns of data. ISAM represents each record as a binary buffer of raw bytes.

FairCom products are unique because the FairCom database engine simultaneously supports these different record formats. The same record can be updated and queried simultaneously as JSON, a SQL row, or a binary buffer using the JSON DB API.

UTF-8

Padding is a feature of the CHAR and BINARY field types. These fieldtypes have a fixed-length that is specified when they are created. Padding allows an application to fill part of the value of one of these fields and the server will fill out the remaining length with a pad character. The pad character defaults to the 0x00 byte. Each table can have its own user-defined pad character.

The JSON DB API uses JSON over HTTP to manage databases, tables, indexes, records, queries, cursors, and transactions. It is available in all FairCom products.

This API is part of FairCom's family of JSON APIs.

Structured Query Language (SQL) is a standardized programming language that is used to manage relational databases and perform various operations on the data in them.

FairCom's SQL engine is ANSI compliant and has almost all SQL features up through the SQL:2003 standard.

The c-tree Database API (CTDB API) is FairCom's database API in the ACE family of APIs. It provides high performance with less code than the FairCom's ISAM API. The CTDB API introduces database concepts that are compatible with SQL. It requires records to contain predefined field structures. FairCom's CTDB API provides full control over record processing. This allows developers to implement data processing algorithms that are tailored to precise application needs, and this allows an application to achieve unrivaled performance. FairCom's CTDB API works well in a variety of languages, such as C, C++, Java, C#, and Visual Basic.

FairCom ACE APIs include ISAM, CTDB, and Low-level ACE API.

Indexed Sequential Access Method (ISAM) is FairCom's primary ACE API. ISAM uses the Record Buffer Method, which gives the application full control over the contents of the entire record buffer to store structured or unstructured data.

FairCom's ISAM API provides full control over record processing. This allows developers to implement data processing algorithms that are tailored to precise application needs, and this allows an application to achieve unrivaled performance. FairCom's ISAM API works best in the C and C++ languages.

FairCom ACE APIs include ISAM, CTDB, and Low-level ACE API.

UTF-8