Queries

Queries are database operations that retrieve data from one or more tables or views. In OpenText™ Analytics Database, the top-level SELECT statement is the query, and a query nested within another SQL statement is called a subquery.

The database is designed to run the same SQL standard queries that run on other databases. However, there are some differences between OpenText™ Analytics Database queries and queries used in other relational database management systems.

The OpenText™ Analytics Database transaction model is different from the SQL standard in a way that has a profound effect on query performance. You can:

• Run a query on a static backup of the database from any specific date and time. Doing so avoids holding locks or blocking other database operations.

• Use a subset of the standard SQL isolation levels and access modes (read/write or read-only) for a user session.

In OpenText™ Analytics Database, the primary structure of a SQL query is its statement. Each statement ends with a semicolon, and you can write multiple queries separated by semicolons; for example:

=> CREATE TABLE t1( ..., date_col date NOT NULL, ...);
=> CREATE TABLE t2( ..., state VARCHAR NOT NULL, ...);