OFFSET FETCH Clause 

OFFSET and FETCH allow you to retrieve data by portions. They specify a row block which you want to get by a single query.

OFFSET offset_row_count {ROW | ROWS}] [FETCH {FIRST | NEXT} fetch_row_count {ROW | ROWS} {ONLY | WITH TIES}]

The offset_row_count or fetch_row_count value can be a number or a literal constant. You can omit fetch_row_count; by default, it equals to 1.

OFFSET specifies the number of rows to skip before starting to return rows from the query result set.

The FETCH specifies the maximum number of rows that can be in the result of a query.

The ONLY option is used to return rows that immediately follow the rows omitted by the OFFSET. In this case the FETCH is an alternative to the LIMIT clause. For example, the following query

SELECT * FROM test_fetch ORDER BY a OFFSET 1 ROW FETCH FIRST 3 ROWS ONLY;

is identical to the query

SELECT * FROM test_fetch ORDER BY a LIMIT 3 OFFSET 1;

The WITH TIES option is used to return any additional rows that tie for the last place in the result set according to the ORDER BY clause. For example, if fetch_row_count is set to 5 but two additional rows match the values of the ORDER BY columns in the fifth row, the result set will contain seven rows.

Examples 

Input table:

┌─a─┬─b─┐
│ 1 │ 1 │
│ 2 │ 1 │
│ 3 │ 4 │
│ 1 │ 3 │
│ 5 │ 4 │
│ 0 │ 6 │
│ 5 │ 7 │
└───┴───┘

Usage of the ONLY option:

SELECT * FROM test_fetch ORDER BY a OFFSET 3 ROW FETCH FIRST 3 ROWS ONLY;

Result:

┌─a─┬─b─┐
│ 2 │ 1 │
│ 3 │ 4 │
│ 5 │ 4 │
└───┴───┘

Usage of the WITH TIES option:

SELECT * FROM test_fetch ORDER BY a OFFSET 3 ROW FETCH FIRST 3 ROWS WITH TIES;

Result:

┌─a─┬─b─┐
│ 2 │ 1 │
│ 3 │ 4 │
│ 5 │ 4 │
│ 5 │ 7 │
└───┴───┘

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