mulander

9 ms·

31.
by mulander 5y ago
The only problem with atomic filesystem snapshots is the time required to perform recovery which can be avoided. The recovery process is of course reliable.
32.
by mulander 5y ago
You are correct and what I had in mind was the required recovery. I do trust recovery but performing it can be very time consuming.
33.
by mulander 5y ago
> I use Gitea(Github clone) locally with SQLite running on ZFS where I can take atomic snapshots of both the SQLite database and git repositories. ZFS snapshots may not result in a consistent databases backup of sqlite. You should use VA
34.
by mulander 5y ago
This is untrue and a sure way to corrupt your database[1]. From sqlite.org on how to corrupt your database: > 1.2. Backup or restore while a transaction is active Systems that run automatic backups in the background might try to make a b
35.
by mulander 6y ago
Let us say that in our example table we have 100 000 records with severit_id < 7, 200 000 with severity_id = 7 and 3 records with severity_id = 8. Statistics claim 100k id < 7, 200k id = 7 and 0 with id > 7. The last 3 updates coul
36.
by mulander 6y ago
> The problem we always ran into with deletes is them triggering full table scans because our indexes weren't set up correctly to test foreign key constraints properly. This is a classic case where partitioning shines. Lets say thos
37.
by mulander 6y ago
No, I don't think statistics can let you get away with this. Databases are concurrent, you can't guarantee that a different session will not insert a record that invalidates your current statistics. You could argue that it should
38.
by mulander 6y ago
Partial indexes are amazing but you have to keep in mind some pecularities. If your query doesn't contain a proper match with the WHERE clause of the index - the index will not be used. It is easy to forget about it or to get it wrong
39.
Universal Relation Data Modelling Considered Harmful(enterprisedb.com)
1 points by mulander 6y ago|0 comments
40.
by mulander 6y ago
An erlang BitTorrent client exists: https://github.com/jlouis/etorrent
41.
by mulander 6y ago
Yes and no or to be precise - to a certain degree but not through an exposed language feature. PostgreSQL still does copy-on-write so the old versions of the row exist and are present in storage. However now there is an autovacuum process g
42.
by mulander 6y ago
> I like how the time travelling/history is always touted as a feature (which it is), but it really just means the garbage collector/pruning part of the transaction engine is missing. Postgres and other mvcc systems could all b
43.
You can now follow people on Google Maps, the company's newest social network(androidpolice.com)
2 points by mulander 6y ago|0 comments
44.
by mulander 6y ago
My mistake, I wrote it from memory instead of copying or looking at the parent post. Edited and fixed.
45.
by mulander 6y ago
> Every tenth man in a group was executed by members of his cohort That is a 10% reduction. Killing nine out of ten would be a 90% reduction but 'in the classical sense' it would also mean that the lucky guy would have to kill
46.
by mulander 6y ago
Not OP but here is one also from HN[1][2] on Mexico. Selected quote from the article: > “It’s good business,” El Polkas says with a shrug. “It makes a lot of money.” When I ask how gasoline compares to narcotics, in terms of overall reve
47.
by mulander 6y ago
Funny historical and architecture fact about PostgreSQL. It actually can do this, for all tables without special features. Unfortunately the facility to perform a query like this is no longer exposed but it shouldn't be impossible to r
48.
by mulander 6y ago
Hi, I'm the guy who did the OpenBSD code reads. The daily started in June 2017 we kept up doing it daily for 42 days straight. In total there were 47 code reads. http://blog.tintagel.pl/2017/06/09/openbsd
49.
JVM Struggles and the Beam(medium.com)
2 points by mulander 6y ago|0 comments
50.
Introduction to Hacking PostgreSQL (2007)(neilconway.org)
169 points by mulander 6y ago|12 comments
51.
by mulander 6y ago
My wife is an animal behaviorist specializing in pastoral dogs, non-lethal prevention of livestock loss and wolves in general. She blogged how simple things like fences[1], live stock guarding dogs[2] and human behavior and awareness[3] can
52.
by mulander 7y ago
> Every time an on-disk database page (4KB) needs to be modified by a write operation, even just a single byte, a copy of the entire page, edited with the requested changes, is written to the write-ahead log (WAL). Physical streaming rep
53.
by mulander 7y ago
You don't need to log every auto explain. Just enable track_io_timing and pg_stat_statements and you get per query IO performance metrics much cheaper. Table F.21. pg_stat_statements Columns https://www.postgresql.org/d
54.
by mulander 7y ago
PostgreSQL has track_io_timing and passing buffers will then include IO timing. \set track_io_timing=on; explain (analyze, verbose, buffers) your-query; Additionally, it will also include things like times for triggers executed from the que
55.
by mulander 7y ago
> Anyone know how connection pooling works with listeners? They don't. LISTEN is per connection and pgbouncer multiplexes many sessions onto a single one. The poller holds the connection and has no way to propagate back the notifica
56.
by mulander 7y ago
> replace rownum <= 1 with LIMIT 1 rownum is a pseudocolumn numbering entries, sorting the results will give you records in non increment rownum. On such queries rownum <= N will give you the record that was first in the results be
57.
by mulander 7y ago
Two years ago I did something similar. Plotting the surviving lines of code in the OpenBSD code base across commits: https://twitter.com/mulander/status/809120593606049792
58.
by mulander 7y ago
> Perl – 1987 > Python – 1989 > Ruby on Rails – 2005 Ruby itself is 1995. In 2005 when Rails was coming out Perl had it's peak according to Tiobe: > Highest Position (since 2001): #3 in May 2005[1] > That makes one wonde
59.
by mulander 7y ago
Undeadly provides more context: https://undeadly.org/cgi?action=article;sid=20190810123007 Including a link to the lobste.rs with comments from stsp@ (main developer on got): https://lobste.rs/s/sxpmar&
60.
by mulander 7y ago
Sure: https://github.com/openbsd/src/commit/707316f931b35ef67f1390...

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