1.3 ac_tables.php

January 22nd, 2026

Contents

• Introduction
• Public Properties
• Methods

1.3.1 Introduction

ac_tables is not designed to replace a full SQL database such as Oracle or the natively supported MariaDB. However, it is designed to bridge the gap on applications where flat file storage is not appropriate but configuring and managing a full RDBMS seems like a time consuming exercise in over-engineering. As a result it has some (intentional) severe limitations compared to SQL. BEAR itself, makes extensive use of ac_tables to keep track of internal configuration data. The table below outlines the main functional difference between ac_tables and a generic SQL implementation.

	ac_tables	SQL RDBMS
Table size	1GiB (recommended default)	TiB
Max columns	unlimited up to 4096 byte file header limit	at least 64
Multi user	No	Yes
User permissions	No	Yes
Strict input type validation	Yes	Yes
Preserved output variable types	Yes	client dependent
Table signing	Yes	Yes
Binary logging	No	Yes
Auto defragmentation	Yes	No
Integrity checking	Yes	Yes
Numerical indexes	Mandatory	RDBMS dependant
Indexes	id column only	Yes
Supports table joins	No	Yes
SQL	No	Yes
Built-in functions and constants	No	Many
Views	No	Yes
Stored procedures	No	Yes
Runs as a service	No	Yes
Supported column types	integers (signed), floating points (signed), characters, enumeration, binary blobs	integers, characters, varcharacters, enumeration, binary blobs, date, datetime, floating points, JSON, XML, GIS etc.
Full text search	No	Yes
Table locking	Yes (process level)	Yes
Row locking	No	Yes
Transactions	No	Yes
Result sorting	Yes (single column only)	Yes (multi-column)
Output limiting	No	Yes
Sub-queries	No	Yes
Complex WHERE clauses	Yes	Yes
Batched UPDATES	Yes	Yes
Batched REPLACE	Yes	Yes
Batched INSERT	Yes	Yes
SHOW TABLES	Yes	Yes
DESCRIBE	Yes	Yes
Intelligent error messages	Yes	Variable
MEMORY / HEAP tables	No	Yes
Character set	UTF-8	Any
Collation	None	User definable
Storage engine	Memory mapped files	Various high performance B-Tree data structures

To use ac_tables it must be instantiated as an object in your PHP code. For example:

$table=new ac_tables; $table->use_table('some_table','password');

or

$table=new ac_tables('some_table','some_password');

Table files are stored with the .act extension but are not referenced as such by ac_tables. ac_tables works on logical table names which are mapped to the filesystem so that a simply hierachy of tables can be created. This means that table names are equivalent to file names minus the .act extension.

For example:

Table file: /bear/web_applications/resources/my_app/some_table.act

Table name: /bear/web_applications/resources/my_app/some_table

ac_tables will never confuse a non .act file for a table.

There is no way to recover a password locked table if the password is forgotten. Although the contents of the table are not encrypted so it may be possible to modify the ac_tables class file to ignore password validation.

About matching rules

ac_tables uses a method based API to make calls instead of an actual query language. Many of the most basic SQL equivelants such as INSERT and REPLACE have directly comparable ac_tables methods. However, a major difference is how ac_tables performs matching (the SQL WHERE clause). SQL supports any number of combinations of AND or OR in the WHERE clause. However, ac_tables is limited to using OR only in the context of individual columns. The following are some basic valid SQL statement patterns with indication as to whether ac_tables can achieve the same effective result or not:

Achievable queries

SELECT FROM table WHERE col1 = "value"; SELECT FROM table WHERE col1 = "value1" AND col2 = "value2"; SELECT FROM table WHERE col1 = "value1" OR col1 = "value2"; SELECT FROM table WHERE col1 IN("value1", "value2"); SELECT FROM table WHERE col1 = "value1" AND (col2 = "value2" OR col2 = "value3"); SELECT FROM table WHERE col1 = "value1" AND col2 IN("value2", "value3"); SELECT FROM table WHERE (col1 = "value1" OR col1 = "value2") AND (col2 = "value3" OR col2 = "value4"); SELECT FROM table WHERE col1 IN("value1", "value2") AND col2 IN("value3", "value4");

Non achievable queries

SELECT FROM table WHERE col1 != "value"; SELECT FROM table WHERE col1 = "value1" OR col2 = "value2"; SELECT FROM table WHERE col1 = "value1" OR (col2 = "value2" OR col2 = "value3"); SELECT FROM table WHERE col1 = "value1" OR col2 IN ("value2", "value3"); SELECT FROM table WHERE col1 = "value1" OR (col1 = "value2" AND col2 = "value3"); SELECT FROM table WHERE (col1 = "value1" OR col1 = "value2") OR (col2 = "value3" OR col2 = "value4"); SELECT FROM table WHERE col1 IN("value1", "value2") OR col2 IN("value3", "value4");

1.3.2 Public Properties

1.3.3 Methods