U testsĮcho "\COPY prumysql FROM PROGRAM 'echo select a,b from prumysql|mysql -h. Mine is called prumysql.Įcho "create table prumysql (a text, b integer) "|PGPASSWORD= psql -t -h. Suppose we want migrate data from a MySQL server to a PostgreSQL server.įirst create the destination table in Postgres. Using \COPY to ingest from other database engines +-+-ħ | Bonaire, Saint Eustatius and Saba | Americaġ3 | Falkland_Islands_(Malvinas) | America U testsĬases | countriesandterritories | continentexp Now we can access the data and calculate, for example, the 10 territories with the lowest number of cases:Įcho "select sum(cases) as cases, countriesAndTerritories, continentexp from covid19casesww group by countriesAndTerritories,continentExp order by 1 asc limit 10 "|PGPASSWORD= psql -h.
We ingest the data into our Postgres server with a pipe from wget to the \COPY commandĮcho "set datestyle to SQL,DMY \COPY covid19casesww FROM PROGRAM 'wget -q -O - ""|tail -n +2' CSV DELIMITER ',' "|PGPASSWORD= psql -t -h. We can continue to use the pipe mechanism from \COPY without parallelism. Unlike parallelized pg_dump / pg_restore, there's no need to move data to a staging file. Test alternative restoration with \COPY (parallelism) Time for j in `echo "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public' and table_type='BASE TABLE' ORDER BY table_name"|./pgsource.sh`Įcho "\copy $j FROM PROGRAM 'echo copy binary $j to STDOUT|./pgsource.sh' WITH BINARY "|./pgdestination.sh Time PGPASSWORD= pg_dump -C -Fc -schema-only -h. Preparation: use pg_dump and psql to move schema.Test data move with \COPY (no parallelism) (See the pg_dump, pg_restore documentation to learn about format options). We’ll need to use the directory format export, and dump to regular files.
COPIES FOR SUPERCOLOR TO BRAKE EVEN COPY FAST FULL
Test full restoration with pg_dump/pg_restore (parallel) Internally, pg_dump and pg_restore uses the COPY command Test full restoration with pg_dump/pg_restore (no parallelism) There are no indexes or foreign keys in this database. My source database has 20 tables each with 1 million auto-generated rows.
Pgdestination.sh = bash script with psql and connection string to destination `tests` database Pgsource.sh = bash script with psql and connection string to source `tests` database That way I can call those scripts when I want to connect. Alternatively, you can consider using a migration service.įor this example, I will be migrating from an Azure Database for PostgreSQL Basic tier single Server to a General Purpose tier single server.įirst, I’ll store the psql connection strings to my source and destination servers in scripts. You’ll have to take additional steps to move those objects. \COPY method does not migrate indexes, foreign keys, and other similar objects.Potential for increased performance with parallelism, compared to pg_dump.\COPY command goes through pipe, so no space required on client side.These are the advantages and disadvantages I expect to see: Then we’ll compare the performance using \COPY. We’ll first move the data with pg_dump, with and without parallelism. Moving data from other database engines, like MySQLįor our first scenario, we’ll do a data migration between two PostgreSQL servers.Migrating data from Postgres to Postgres.Today, we’ll use \COPY to enable these three scenarios: You need to have the psql application to be able to use \COPY. You can even use both absolute and relative paths. The source file does not have to exist on the same machine as the Postgres instance if you use \COPY. \COPY runs COPY internally, but with expanded permissions and file access. The server based COPY command has limited file access and user permissions, and isn’t available for use on Azure Database for PostgreSQL. Postgres's COPY comes in two separate variants, COPY and \COPY: COPY is server based, \COPY is client based.” - The PostgreSQL Wikiīoth versions of COPY move data from a file to a Postgres table. “ COPY is the Postgres method of data-loading. Today, we’re exploring three scenarios where you can consider using PostgreSQL’s COPY command. The method you pick depends on the scenario you want to enable. When you want to move data into your PostgreSQL database, there are a few options available like pg_dump and Azure Data Factory.
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