SQLite

7 ms·

1.
by SQLite 16d ago
Checksums use CPU cycles. SQLite will do checksums with an extension ( https://sqlite.org/cksumvfs.html ) but that is off by default since an overwhelming majority of developers are more interested in day-to-day performance
2.
by SQLite 1mo ago
SQLite file format spec: < https://sqlite.org/fileformat.html >
3.
by SQLite 1mo ago
Correct. You will have great difficulty hitting this problem, even if you deliberately try. The only app I've ever known to hit this problem was Tailscale, and that was because they were running sqlite3_wal_checkpoint() four times per
4.
by SQLite 5mo ago
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 take turns. SQLite prevents two or more writes from runn
5.
by SQLite 6mo ago
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 say you will be hard pressed to find a dataset of significa
6.
by SQLite 6mo ago
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 reliability in a scripting language (like SQL or JSON)
7.
by SQLite 6mo ago
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 column that holds a JSON object, then jjj->>'xy
8.
by SQLite 6mo ago
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 random passers-by on the internet. But SQLite does accept out
9.
by SQLite 6mo ago
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 should be fine.
10.
by SQLite 7mo ago
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 than 15 million test cases. It is true that the ha
11.
by SQLite 8mo ago
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 >.
12.
by SQLite 9mo ago
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 message. But if you get an I/O error with mma
13.
by SQLite 9mo ago
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, logically require reading the whole input in order to compute th
14.
by SQLite 9mo ago
Website updated with more precise wording. Sorry for the confusion.
15.
by SQLite 9mo ago
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 SQLite core with licensed code. Please put t
16.
by SQLite 9mo ago
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 gave me the idea of doing a distributed VCS and sto
17.
by SQLite 11mo ago
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.
18.
by SQLite 1y ago
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&#
19.
by SQLite 1y ago
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 expression on the partial index and Q is th
20.
by SQLite 1y ago
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 capabilities in SQLite's parser that allows keywords to b
21.
by SQLite 1y ago
> 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 down into SQLite. It is a single token recognized by the S
22.
by SQLite 1y ago
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 that (1) it is fully enc
23.
by SQLite 1y ago
> 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 supported page sizes between 512 and 32768, though, and s
24.
by SQLite 1y ago
> 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, see https://sqlite.org/flextypegoo
25.
by SQLite 1y ago
> 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 transactions are durable across application crashes (or S
26.
by SQLite 1y ago
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.
27.
by SQLite 1y ago
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 downside of this is that the origin database will block al
28.
by SQLite 1y ago
I claim the edit is neither a hardening nor a softening but rather a clarification and an attempt to better explain the original intent.
29.
by SQLite 2y ago
SQLite supports indexes on expressions. So if you have an expression that accesses some subcomponent of JSON that you want to index, just create an index on that expression.
30.
by SQLite 2y ago
Seeing this pop up on HN prompted me to review the 13-year-old document, and bring it up to date with the latest enhancements to SQLite. Specifically, three ways for safely backing up a live SQLite database are now listed in section 1.2.

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