Extension:EImage/ei cache table

The ei_cache table was introduced since version 3.3, and schema has been fixed since version 3.4.

ei_id
Numeric id item of the clip. This is an auto-incrementing primary key.

ei_eid
Basic identifier of the clip. In real the sha1 checksum content value from the 'ei_clip' field. EImage use it for identification of the clip before load of source.

ei_clip
Set of the attributes used for clip create. Next instances use same clip, if source is same and attributes without change.

ei_file
Sha1 checksum of the clip content, which is storage in cache. It's base string for clip and thumbnail name, and key for 'ei_pages' table items.

ei_origin_exif
Original exif tags exported from source file, saved as JSON.

ei_counter
Counter of the clip use.

ei_width
Width of the clip. It's need if EImage use the clip from cache.

ei_height
Height of the clip It's need if EImage use the clip from cache.

ei_ctime
Timestamp of the clip create.

ei_expire
Limit of the expiration.

ei_type
Number for mimetype identify of the clip.

Schema summary
++-+--+-+-++ ++-+--+-+-++ ++-+--+-+-++
 * Field         | Type                | Null | Key | Default | Extra          |
 * ei_id         | int(10) unsigned    | NO   | PRI | NULL    | auto_increment |
 * ei_eid        | varbinary(40)       | NO   | MUL | NULL    |                |
 * ei_clip       | longblob            | YES  |     | NULL    |                |
 * ei_file       | varbinary(40)       | YES  |     | NULL    |                |
 * ei_origin_exif | longblob           | YES  |     | NULL    |                |
 * ei_counter    | int(11)             | NO   |     | 0       |                |
 * ei_width      | int(11)             | NO   |     | 0       |                |
 * ei_height     | int(11)             | NO   |     | 0       |                |
 * ei_ctime      | binary(14)          | NO   |     | NULL    |                |
 * ei_expire     | binary(14)          | NO   | MUL | NULL    |                |
 * ei_type       | tinyint(3) unsigned | NO   |     | 0       |                |

Indexes
 +--+++--+-+---+-+--++--++-+---+ +--+++--+-+---+-+--++--++-+---+ +--+++--+-+---+-+--++--++-+---+
 * Table   | Non_unique | Key_name       | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
 * ei_cache |         0 | PRIMARY        |            1 | ei_id       | A         |           9 |     NULL | NULL   |      | BTREE      |         |               |
 * ei_cache |         0 | ei_eid_create  |            1 | ei_eid      | A         |           9 |     NULL | NULL   |      | BTREE      |         |               |
 * ei_cache |         0 | ei_eid_create  |            2 | ei_file     | A         |           9 |     NULL | NULL   | YES  | BTREE      |         |               |
 * ei_cache |         1 | ei_expire_time |            1 | ei_expire   | A         |           2 |     NULL | NULL   |      | BTREE      |         |               |