yangyang

16 ms·

31.
by yangyang 10y ago
I run Emacs under termux on my Nexus 6P. Works great with exactly the same config I use on the desktop.
32.
by yangyang 11y ago
I've uploaded a little video of it in action here: https://www.youtube.com/watch?v=NIG7UfFYCdY
33.
by yangyang 11y ago
Er, I'd have to say that at the moment it's almost certainly just me :-). I have two of these clocks, and I'm planning to put one in an enclosure and give it to my niece, so I suppose then there will be two. I don't thin
34.
by yangyang 11y ago
On a related note, I wrote a Tetris clone [1] for the JY-MCU-3208 "dot matrix clock" [2] available from DX.com, Banggood etc., recently. It's in C, runs on the ATmega8L on this clock. [1] https://github.com/ho
35.
XTIDE Universal BIOS(code.google.com)
44 points by yangyang 11y ago|6 comments
36.
by yangyang 11y ago
Well that's pretty much what a hash join is doing - scan a table creating a hash table (effectively an in-memory index), then scan the inner table looking up values in the hash table. A hash table is a more effective data structure tha
37.
Scientist Trained Rats to Trade, and Win, on Wall Street(vice.com)
6 points by yangyang 12y ago|2 comments
38.
Will the UK's gas holders be missed?(bbc.co.uk)
6 points by yangyang 12y ago|0 comments
39.
by yangyang 12y ago
Some interesting ideas here. One thing I noted in a quick play with it on Windows: if you right-drag outside the window, it doesn't get the mouse-up event and you have to right click in the window again to stop it panning.
40.
by yangyang 12y ago
I'd be very interested to know more about this too. There is considerable overhead for each row in PostgreSQL (24 byte header, which must be aligned). Obviously you'll save a bit if there are repeated keys higher up, but you'
41.
by yangyang 12y ago
Amazon RDS for PostgreSQL also supports SSDs [1]: "Amazon RDS now supports General Purpose (SSD) Storage You can now launch DB Instances that use General Purpose (SSD) storage, a new SSD-backed storage option for Amazon RDS" [1]
42.
by yangyang 12y ago
Also, if you have any untrusted PLs available, a superuser can create one of those and do what they like.
43.
by yangyang 12y ago
Apologies - I was thinking of ALTER SYSTEM [1]. That writes to postgresql.auto.conf. It sounds like that file has priority over postgresql.conf [2]. You might well be able to just prevent writes by the postgres user (or whatever user you&#x
44.
by yangyang 12y ago
That sounds sensible, thanks; I'd misunderstood and thought you were doing continuous replication to another PG server, now I realise you're archiving WAL to S3.
45.
by yangyang 12y ago
OK, that sounds fair enough. Just interested in whether you'll be running a patched Postgres to be honest :-). There is of course set_config in 9.4 - superusers can then edit the config file through that (a superuser can overwrite any
46.
by yangyang 12y ago
How does that tie in with your admin of the database? What happens when a user changes wal_level or something? Just wondering where you draw the line.
47.
by yangyang 12y ago
Do clients get Postgres superuser access?
48.
by yangyang 12y ago
Replication and backup solve different problems. What if I accidentally drop a table and need last night's backup? Are they archiving the WALs too so you can do point-in-time recovery?
49.
by yangyang 12y ago
Are the SSDs at Digital Ocean enterprise grade and RAIDed? They won't corrupt data under power loss etc? Bearing in mind you're probably using asynchronous replication, people you can't rely on that for durability; people wil
50.
by yangyang 12y ago
Thanks. I'm not involved with it, just a Postgres user and thought it was of interest.
51.
by yangyang 12y ago
This is really interesting. Did you do anything about join pushdown (which isn't supported in core PostgreSQL yet)? Apologies if this is in your talk - I looked at the slides and couldn't see anything.
52.
Vitesse Data: Postgres + LLVM(vitessedata.com)
257 points by yangyang 12y ago|37 comments
53.
by yangyang 12y ago
Indeed: it's estimating that a single row will be returned from the seq scan. That will clearly take no time to sort!
54.
by yangyang 12y ago
The time taken parsing the query is insignificant compared to the time planning. Not sure if it's exactly what you're getting at, but SQL Server has a "USE PLAN" hint that lets you set the entire query plan (using an XML
55.
by yangyang 12y ago
Have you seen QUEL ( http://en.wikipedia.org/wiki/QUEL_query_languages )? It's the original query language used by Postgres (it gives the client library, libpq, its name). It's not there any more - it was repla
56.
by yangyang 12y ago
It can estimate though, using per-column statistics. ANALYZE (and the autoanalyze background process) update these in PostgreSQL. These stats are a huge part of cost-based query optimisation, which all major DBMSs do these days. Details her
57.
by yangyang 12y ago
That query improvement was for a third-party extension storing data outside PostgreSQL (cstore_fdw), and has no effect on core Postgres.
58.
by yangyang 12y ago
There are doors but they are not for use in normal circumstances. The new Victoria Line trains were initially supposed to be "space trains", open all the way through, but didn't actually end up getting built like that.
59.
by yangyang 12y ago
They'd probably never close in some stations, like Victoria at rush hour :-)
60.
PostgreSQL 9.4 Beta 3 Released(postgresql.org)
2 points by yangyang 12y ago|0 comments

More ›