Re: [sqlite] SQLite4 key encoding -- Is it ever decoded?

On Tue, Jul 24, 2012 at 8:29 AM, Steven E. Harris wrote: > Richard Hipp writes: >> Many keys can be decoded, but for TEXT keys with application-defined >> collating sequences, the encoding is not reversible. Many applications >> will

Re: [sqlite] SQLite4 key encoding -- Is it ever decoded?

On Tue, Jul 24, 2012 at 9:29 AM, Steven E. Harris wrote: > > If, as you say, SQLite cannot (or will not) extract values from an > encoded key, then does the covering index really just encode column > values a and b as the key, and store values for c and d in a record >

Re: [sqlite] SQLite4 key encoding -- Is it ever decoded?

On 24 Jul 2012, at 2:29pm, "Steven E. Harris" wrote: > A (too) literal reading of this would suggest that the index is the > key-encoded concatenation of -- to use the example from that first Wiki > page -- four values for columns a, b, c, and d. However, if one were to > query

Re: [sqlite] SQLite4 key encoding -- Is it ever decoded?

Richard Hipp writes: > It would be convenient to be able to decode the keys. But it is not > possible to do so, in general. This, then, takes my inquiry to the topic of covering indices. On the "The Design of SQLite4" Wiki page¹, it says (emphasis

Re: [sqlite] SQLite4 key encoding -- Is it ever decoded?

On Tue, Jul 17, 2012 at 8:46 AM, Steven E. Harris wrote: > Per my recent posted messages here, I've been studying the data formats > for SQLite4. This question concerns the key encoding and how it is used. > > It's clear that the key encoding format is designed to allow >

[sqlite] SQLite4 key encoding -- Is it ever decoded?

Per my recent posted messages here, I've been studying the data formats for SQLite4. This question concerns the key encoding and how it is used. It's clear that the key encoding format is designed to allow lexicographic ordering of compound keys comprising concatenated attribute values, and that