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@dat-vikash
dat-vikash / postgres_queries_and_commands.sql
Created September 3, 2020 19:37 — forked from rgreenjr/postgres_queries_and_commands.sql
Useful PostgreSQL Queries and Commands
-- show running queries (pre 9.2)
SELECT procpid, age(clock_timestamp(), query_start), usename, current_query
FROM pg_stat_activity
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
ORDER BY query_start desc;
-- show running queries (9.2)
SELECT pid, age(clock_timestamp(), query_start), usename, query
FROM pg_stat_activity
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%'
@dat-vikash
dat-vikash / asciiputsonglasses
Created May 3, 2018 15:14 — forked from staringispolite/asciiputsonglasses
Ascii art sunglasses meme
Puts on glasses:
(•_•)
( •_•)>⌐■-■
(⌐■_■)
Takes off glasses ("mother of god..."):
(⌐■_■)
( •_•)>⌐■-■
@dat-vikash
dat-vikash / faster_toPandas.py
Created February 27, 2018 12:52 — forked from joshlk/faster_toPandas.py
PySpark faster toPandas using mapPartitions
import pandas as pd
def _map_to_pandas(rdds):
""" Needs to be here due to pickling issues """
return [pd.DataFrame(list(rdds))]
def toPandas(df, n_partitions=None):
"""
Returns the contents of `df` as a local `pandas.DataFrame` in a speedy fashion. The DataFrame is
repartitioned if `n_partitions` is passed.
@dat-vikash
dat-vikash / latency.txt
Created October 24, 2016 23:32 — forked from jboner/latency.txt
Latency Numbers Every Programmer Should Know
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
// Create the Global class in your /app folder root package:
import play.api.{GlobalSettings, Play}
import play.api.Play.current
import play.api.mvc._
import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global
/**