Viewing profile — SQLite

SQLite allows multiple writers. The constraint is that only one of how writers can be actively writing at any moment in time. If there are multiple processes wanting to write, they…

Checking the datatype is not the same as validating. There is lots of data out there that is invalid, and yet still has the correct type. In fact, that is the common case. I dare s…

No, I think that people can use SQLite anyway they want. I'm glad people find it useful. I do remain perplexed, though, about how people continue to think that rigid typing helps r…

Flexible typing works really well with JSON, which is also flexibly typed. Are you familiar with the ->> operator that extracts a value from JSON object or array? If jjj is a colum…

Minor correction: SQLite is not closed to contributions. It just has an unusually high bar to accepting contributions. The project does not commonly accept pull requests from rando…

As long as you are not using indexes on expressions where the expression value is a floating point number that is computed using one or more text->binary conversions, then you shou…

You do not recall correctly. There is more than 500K SLOC of test code in the public source tree. If you "make releasetest" from the public source tarball on Linux, it runs more th…

The Common Table Expression feature of SQL is very good at walking graphs. See, for example https://sqlite.org/lang_with.html#queries_against_a_graph >.

If an I/O error happens with read()/write(), you get back an error code, which SQLite can deal with and pass back up to the application, perhaps accompanied by a reasonable error m…

That depends on the query. SQLite tries to use LIMIT to restrict the amount of reading that it does. It is often successful at that. But some queries, by their very nature, logical…

Website updated with more precise wording. Sorry for the confusion.

No, Simon, we don't "refuse". We are just very selective and there is a lot of paperwork involved to confirm the contribution is in the public domain and does not contaminate the S…

The story of Fossil: Something better than CVS was needed. (I'm not being critical of CVS. I had to use the VCSes that can before, and CVS was amazing compared to them.) Monochrome…

SQLite runs about 5 times faster compiled with GCC (13.3.0) than it does when compiled with FIL-C. And the resulting compiled binary from GCC is 13 times smaller.

The top-level routine is here: https://sqlite.org/src/info/aae36a5fbd17?ln=6767-6818 >. Small (32-bit) integer literals are compared numerically, here: https://sqlite.org/src/info/…

Yeah, but who ever writes "x=0.9" as a constraint on a partial index? Really? Don't you know you aren't suppose to compare floating point quantities for equality? If P is the expre…

I think (I hope!) we are probably done adding keywords to SQLite. Furthermore, all of the more recently added keywords (ex: WITHIN, RETURNING, MATERIALIZED) make use of special cap…

> Is there an SQL injection attack vulnerability there? No, at least not if you put the SQL inside of {...}, which IIRC the documentation strongly recommends. The $uid is passed do…

The paper is from 2017. Fossil got chat support in 2021 and the developers now use Fossil-chat. https://fossil-scm.org/home/doc/trunk/www/chat.md Fossil chat has the advantages tha…

> Why not just have the value be the base 2 logarithm of the page size, i.e. a value between 9 and 16? Yes, that would have been a better choice. Originally, the file format only s…

> Dr. Hipp has said several times that nobody expected a weakly-typed database to achieve the pervasiveness that is observed with SQLite. I don't remember ever saying that. Rather,…

> sqlite in its default (journal_mode = DELETE) is not durable. Not true. In its default configuration, SQLite is durable. If you switch to WAL mode, the default behavior is that t…

Update: This enhancement is now on trunk and will be included in the 3.50.0 release of SQLite due out in about four weeks.

I just checked in an experimental change to sqlite3_rsync that allows it to work on non-WAL-mode database files, as long as you do not use the --wal-only command-line option. The d…

I claim the edit is neither a hardening nor a softening but rather a clarification and an attempt to better explain the original intent.