Ferret File System/v0.1/SQL/firev: Difference between revisions
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(basing new table on fideals; doc reorg & expansion) |
(Note about FileMean (future)) |
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* '''Descr''' should describe, if known, what distinguishes this firev from other firevs of the same fideal (or from the parent firev, if there is one). | * '''Descr''' should describe, if known, what distinguishes this firev from other firevs of the same fideal (or from the parent firev, if there is one). | ||
* '''FileHash''' is a unique fingerprint (hash) of the file, using an algorithm unlikely to produce duplicate hashes for even the smallest variation. See [http://us3.php.net/manual/en/function.hash.php hash()] for details; apparently these can be as long as 128 hexadecimal digits = 64 bytes. | * '''FileHash''' is a unique fingerprint (hash) of the file, using an algorithm unlikely to produce duplicate hashes for even the smallest variation. See [http://us3.php.net/manual/en/function.hash.php hash()] for details; apparently these can be as long as 128 hexadecimal digits = 64 bytes. | ||
I think we're also going to want a field, possibly called '''FileMean''', which changes very little (or not at all) when there are small changes to the data. This should make it easier to connect firevs to a fideal. | |||
===Rules=== | ===Rules=== | ||
* '''isDelib''' and '''isAccid''' can both be FALSE if the cause of the firev is not known (i.e. we know there's a knew firev, but not whether it was deliberate or accidental), but they cannot both be TRUE. | * '''isDelib''' and '''isAccid''' can both be FALSE if the cause of the firev is not known (i.e. we know there's a knew firev, but not whether it was deliberate or accidental), but they cannot both be TRUE. | ||
Revision as of 18:46, 25 December 2012
About
"Firev" is short for "file revision". A firev is a particular series of byte values that represents a particular revision, or version, of a Ferret File System/v0.1/SQL/terms/fideal. Fideal records are generally only created when multiple copies of the same file are found, though they may also be created manually in order to track more information about a file.
A firev can be created either deliberately (as a result of user editing) or accidentally (imperfect transcription, drive corruption, viral infection).
Fields
- isDelib: TRUE if this is known to be a deliberate user edit of the parent firev (must be FALSE if isAccid is TRUE)
- isAccid: TRUE if this is known to be an accidental corruption of the parent firev (must be FALSE if isDelib is TRUE)
- Descr should describe, if known, what distinguishes this firev from other firevs of the same fideal (or from the parent firev, if there is one).
- FileHash is a unique fingerprint (hash) of the file, using an algorithm unlikely to produce duplicate hashes for even the smallest variation. See hash() for details; apparently these can be as long as 128 hexadecimal digits = 64 bytes.
I think we're also going to want a field, possibly called FileMean, which changes very little (or not at all) when there are small changes to the data. This should make it easier to connect firevs to a fideal.
Rules
- isDelib and isAccid can both be FALSE if the cause of the firev is not known (i.e. we know there's a knew firev, but not whether it was deliberate or accidental), but they cannot both be TRUE.
History
- 2012-12-25 Adapted/created from fideals
SQL
<mysql>CREATE TABLE `fideals` (
`ID` INT NOT NULL AUTO_INCREMENT, `ID_Fideal` INT DEFAULT NULL COMMENT "ID of ideal file", `ID_Parent` INT DEFAULT NULL COMMENT "ID of parent firev, if any", `isDelib` BOOL DEFAULT FALSE COMMENT "TRUE = this is known to be a deliberate user edit of the parent", `isAccid` BOOL DEFAULT FALSE COMMENT "TRUE = this is known to be an accidental corruption of the parent", `Descr` VARCHAR(255) COMMENT "description of differences", `FileSize` INT COMMENT "correct file size in bytes", `FileHash` VARBINARY(64) COMMENT "unique hash", PRIMARY KEY(`ID`)
) ENGINE = MYISAM;</mysql>