This documentation is for an unreleased version of Apache Flink Table Store. We recommend you use the latest stable version.
Query Table #
You can directly SELECT the table in batch runtime mode of Flink SQL.
-- Batch mode, read latest snapshot SET 'execution.runtime-mode' = 'batch'; SELECT * FROM MyTable;
Query Engines #
Table Store not only supports Flink SQL queries natively but also provides queries from other popular engines. See Engines
Query Optimization #
It is highly recommended to specify partition and primary key filters along with the query, which will speed up the data skipping of the query.
The filter functions that can accelerate data skipping are:
Table Store will sort the data by primary key, which speeds up the point queries and range queries. When using a composite primary key, it is best for the query filters to form a leftmost prefix of the primary key for good acceleration.
Suppose that a table has the following specification:
CREATE TABLE orders ( catalog_id BIGINT, order_id BIGINT, ....., PRIMARY KEY (catalog_id, order_id) NOT ENFORCED -- composite primary key )
The query obtains a good acceleration by specifying a range filter for the leftmost prefix of the primary key.
SELECT * FROM orders WHERE catalog_id=1025; SELECT * FROM orders WHERE catalog_id=1025 AND order_id=29495; SELECT * FROM orders WHERE catalog_id=1025 AND order_id>2035 AND order_id<6000;
However, the following filter cannot accelerate the query well.
SELECT * FROM orders WHERE order_id=29495; SELECT * FROM orders WHERE catalog_id=1025 OR order_id=29495;