column-oriented DB
Free and open-source software Columnar DB Database Name Language Implemented in Notes Apache Druid Java started in 2011 for low-latency massive ingestion and queries Apache Kudu C++ released in…
mysql transcations
Generally how to write transaction Begin transaction by issuing the SQL command BEGIN WORK. Issue one or more SQL commands like SELECT, INSERT, UPDATE or DELETE. Check if there is no…
Geocoding 40 millions US addresses totally free with PostGIS 2.1 on debian 8
Postgis 2.1 ( on debian 8) make geocoding US addresses ( about 40 Million ) quite easy, and it is totally free! Thanks for the PostGIS and PostGRESQL open source…
Postgresql cheatsheat
Connecting to MySQL: mysql -u user_name -p Connecting to PostgreSQL: sudo -u postgres psql Description MySQL command PostgreSQL equivalent Show databases SHOW DATABASES; \l[ist] Use/Connect to a database named ‘some_database’ USE…
MySQL Binary field how to insert, search
http://www.ovaistariq.net/632/understanding-mysql-binary-and-non-binary-string-data-types/ http://artarmstrong.com/blog/2014/12/07/store-uuid-as-binary16-mysql-data-type/ http://stackoverflow.com/questions/9081216/mysql-insert-statement-to-binary-datatype e.g: CREATE TABLE `Test` ( `myhash` binary(16) DEFAULT NULL ) Insert 10E8400E29B11D4A716446655440000 as HEX representation of some chars Insert into `Test` values ( UNHEX(“110E8400E29B11D4A716446655440000”) ); MySQL standard…
