postgresql-9.5

I have two columns in table col1 , col2 , they both are unique indexed (col1 is unique and so is col2). I need at insert into this table, use ON CONFLICT syntax and update other columns, but I can't use both column in conflict_target clause. It works: INSERT INTO table ... ON CONFLICT ( col1 ) DO UPDATE SET -- update needed columns here But how to do this for several columns, something like this: ... ON CONFLICT ( col1, col2 ) DO UPDATE SET .... e4c5 A sample table and data CREATE TABLE dupes(col1 int primary key, col2 int, col3 text, CONSTRAINT col2_unique UNIQUE (col2) ); INSERT INTO dupes

Disclaimer: theoretical question. Several questions here was asked about how to differentiate inserted and updated rows in the PostgreSQL upsert statement. Here is a simple example: nd@postgres=# create table t(i int primary key, x int); nd@postgres=# insert into t values(1,1); nd@postgres=# insert into t values(1,11),(2,22) on conflict(i) do update set x = excluded.i*11 returning *, xmin, xmax; ╔═══╤════╤══════╤══════╗ ║ i │ x │ xmin │ xmax ║ ╠═══╪════╪══════╪══════╣ ║ 1 │ 11 │ 7696 │ 7696 ║ ║ 2 │ 22 │ 7696 │ 0 ║ ╚═══╧════╧══════╧══════╝ So, xmax > 0 (or xmax = xmin ) - row was updated; xmax

I have table create table big_table ( id serial primary key, -- other columns here vote int ); This table is very big, approximately 70 million rows, I need to query: SELECT * FROM big_table ORDER BY vote [ASC|DESC], id [ASC|DESC] OFFSET x LIMIT n -- I need this for pagination As you may know, when x is a large number, queries like this are very slow. For performance optimization I added indexes: create index vote_order_asc on big_table (vote asc, id asc); and create index vote_order_desc on big_table (vote desc, id desc); EXPLAIN shows that the above SELECT query uses these indexes, but it's