I hereby claim:
- I am aknysh on github.
- I am aknysh (https://keybase.io/aknysh) on keybase.
- I have a public key ASAr9J94yCRnnpqBq7dDrV3Sp3Aof-ZAGrPMRmChsuNC1Ao
To claim this, I am signing this object:
I hereby claim:
To claim this, I am signing this object:
Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.
$ python -m SimpleHTTPServer 8000
Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.
$ python -m SimpleHTTPServer 8000
Latency Comparison Numbers | |
-------------------------- | |
L1 cache reference 0.5 ns | |
Branch mispredict 5 ns | |
L2 cache reference 7 ns 14x L1 cache | |
Mutex lock/unlock 25 ns | |
Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
Compress 1K bytes with Zippy 3,000 ns 3 us | |
Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
with table_stats as ( | |
select psut.relname, | |
psut.n_live_tup, | |
1.0 * psut.idx_scan / greatest(1, psut.seq_scan + psut.idx_scan) as index_use_ratio | |
from pg_stat_user_tables psut | |
order by psut.n_live_tup desc | |
), | |
table_io as ( | |
select psiut.relname, | |
sum(psiut.heap_blks_read) as table_page_read, |