Your first SQL program

Feldera only supports two kinds of SQL Data Definition Language (DDL) statements: table definitions, and view definitions. Each table definition becomes an input, and each view definition becomes an output. Here is an example program:

CREATE TABLE person
(
    name    VARCHAR,
    age     INT,
    present BOOLEAN
);
CREATE MATERIALIZED VIEW adult AS SELECT person.name, person.age FROM person WHERE person.age > 18;

Statements need to be separated by semicolons.

Incremental view maintenance

Feldera is optimized for performing incremental view maintenance. In consequence, Feldera programs in SQL are expressed as VIEWS, or standing queries. A view is a virtual table that is formed by a query on other tables or views.

For example, the following query defines a view:

CREATE MATERIALIZED VIEW adult AS SELECT person.name FROM person WHERE person.age > 18

In order to interpret this query the compiler needs to have been given a definition of table (or view) Person. The table Person must be defined using a SQL DDL statement, e.g.:

CREATE TABLE person
(
    name    VARCHAR,
    age     INT,
    present BOOLEAN
)