postgres copy data from one table to another

Postgres copy data from one table to another serial#

If (and only if) you actually find that the performance is unacceptably slow, then you might look at other options. It depends on many issues (size and nature of the data, quality of the statistics in the System Catalog, speed of the hardware, usage load, and much more). Since a view is a virtual table and not a 'real' (base) table, you're actually executing a (perhaps complex) query every time you access it. Since a view is a 'window' (NOT a shapshot) on the 'real' data in the base table, you can add/update/delete on your base table and simply re-query the view scenarios with no need to recreate anything as the data changes over time.There is no need to redefine or copy them. The indexes already in use for the base table (your original, 'real' table) will be used (as seen fit by the query optimizer) when you query each view/scenario.You never duplicate any portion of your data.There are several benefits to this approach: Every time you query the view the database server looks up the underlying query that defines it and executes that (ANDed with any other conditions you used).

Views are stored in the database (in the System Catalog) as their defining query. E.g., if you want a 'window' on the data where you 'deleted' the rows where X=Y, then you would create a view as rows where (X != Y). I.e., define a view based on what you want to INclude. You could define a view for each scenario you want to test based on the negation of what you want to exclude. Since you are doing 'what if'-type analysis on the data, I wonder if might you be better off using views. Using pg_dump with some clever options and perhaps editing the output before pg_restoring might do the trick. If you are using PostgreSQL pre-8.3, you can simply use pg_dump with option '-t' to specify 1 table, change table name in dump, and load it again: => pg_dump -t x2 | sed 's/x2/x3/g' | psql NOTICE: CREATE TABLE / UNIQUE will create implicit index 'x2_x_key' for table 'x2' NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index 'x2_pkey' for table 'x2' Now we can copy the structure: # create table x2 ( like x1 INCLUDING DEFAULTS INCLUDING CONSTRAINTS INCLUDING INDEXES )

if oid in firstappofferVendor is equal to firstappbid.offerid then userid should be copied to vendorid. Id | integer | not null default nextval('x1_id_seq'::regclass) I want to copy column Userid from public.'firstappofferVendor' to table firstappbid on the basis of oid, i.e.

NOTICE: CREATE TABLE / UNIQUE will create implicit index 'x1_x_key' for table 'x1' NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index 'x1_pkey' for table 'x1'

Postgres copy data from one table to another serial#

NOTICE: CREATE TABLE will create implicit sequence 'x1_id_seq' for serial column 'x1.id' Now, let's create table: # create table x1 (id serial primary key, x text unique) New PostgreSQL ( since 8.3 according to docs ) can use 'INCLUDING INDEXES': # select version()