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Appendix

Keywords

The following table shows all keywords in the language.

keyword description example
ADD add a column to a stream or table ADD (COLUMN)? identifier type;
ADVANCE hop size in hopping window WINDOW HOPPING (SIZE 30 SECONDS, ADVANCE BY 10 SECONDS)
ALL list hidden topics SHOW ALL TOPICS;
ALTER change a property, stream, or table ALTER 'auto.offset.reset'='latest';
AND logical "and" operator WHERE userid<>'User_1' AND userid<>'User_2'
ARRAY one-indexed array of elements SELECT ARRAY[1, 2] FROM s1 EMIT CHANGES;
AS alias a column, expression, or type
ASSERT assert value, stream, table, tombstone ASSERT NULL VALUES sourceName (columns)? KEY values;
BEGINNING print from start of topic PRINT <topic-name> FROM BEGINNING;
BETWEEN constrain a value to a range SELECT event FROM events WHERE event_id BETWEEN 10 AND 20 …
BY specify expression GROUP BY regionid, ADVANCE BY 10 SECONDS, PARTITION BY userid
CASE select a condition from expressions SELECT CASE WHEN condition THEN result [ WHEN … THEN … ] … END
CAST change expression type SELECT id, CONCAT(CAST(COUNT(*) AS VARCHAR), '_HELLO') FROM views …
CHANGES specify incremental refinement type SELECT * FROM users EMIT CHANGES;
CONNECTOR manage a connector CREATE SOURCE CONNECTOR 'jdbc-connector' WITH( …
CONNECTORS list all connectors SHOW CONNECTORS;
CREATE create an object CREATE STREAM rock_songs (artist VARCHAR, title VARCHAR) …
DATE date data type
DAY time unit of one day for a window WINDOW TUMBLING (SIZE 30 SECONDS, RETENTION 1 DAY)
DAYS time unit of days for a window WINDOW TUMBLING (SIZE 30 SECONDS, RETENTION 1000 DAYS)
DECIMAL decimal numeric type
DEFINE define a variable DEFINE name = 'Tom Sawyer';
DELETE remove a Kafka topic DROP TABLE <table-name> DELETE TOPIC;
DESCRIBE list details for object(s) DESCRIBE PAGEVIEWS;
DISTINCT test for uniqueness CREATE STREAM output AS SELECT A, A IS NOT DISTINCT FROM 1,…);
DROP delete an object DROP CONNECTOR <connector-name>;
ELSE condition in WHEN statement CASE WHEN units<2 THEN 'sm' WHEN units<4 THEN 'med' ELSE 'large' …
EMIT specify push query SELECT * FROM users EMIT CHANGES;
END close a CASE block SELECT CASE WHEN condition THEN result [ WHEN … THEN … ] … END
EXISTS test whether object exists DROP STREAM IF EXISTS <stream-name>;
EXPLAIN show execution plan EXPLAIN <query-name>; or EXPLAIN <expression>;
EXTENDED list details for object(s) DESCRIBE <stream-name> EXTENDED;
FALSE Boolean value of false
FROM specify record source for queries SELECT * FROM users;
FULL specify FULL JOIN CREATE TABLE t AS SELECT * FROM l FULL OUTER JOIN r ON l.ID = r.ID;
FUNCTION list details for a function DESCRIBE FUNCTION <function-name>;
FUNCTIONS list all functions SHOW FUNCTIONS;
GRACE grace period for a tumbling window WINDOW TUMBLING (SIZE 1 HOUR, GRACE PERIOD 2 HOURS)
GROUP group rows with the same values SELECT regionid, COUNT(*) FROM pageviews GROUP BY regionid
HAVING condition expression GROUP BY card_number HAVING COUNT(*) > 3
HOPPING specify a hopping window WINDOW HOPPING (SIZE 30 SECONDS, ADVANCE BY 10 SECONDS)
HOUR time unit of one hour for a window WINDOW TUMBLING (SIZE 1 HOUR, RETENTION 1 DAY)
HOURS time unit of hours for a window WINDOW TUMBLING (SIZE 2 HOURS, RETENTION 1 DAY)
IF test whether object exists DROP STREAM IF EXISTS <stream-name>;
IN specify multiple values WHERE name IN (value1, value2, ...)
INNER specify INNER JOIN CREATE TABLE t AS SELECT * FROM l INNER JOIN r ON l.ID = r.ID;
INSERT insert new records in a stream/table INSERT INTO <stream-name> ...
INTEGER integer numeric type CREATE TABLE profiles (id INTEGER PRIMARY KEY, …
INTERVAL number of messages to skip in PRINT PRINT <topic-name> INTERVAL 5;
INTO stream/table to insert values INSERT INTO stream_name ...
IS use with keywords like NOT and DISTINCT CREATE STREAM output AS SELECT A, A IS NOT DISTINCT FROM 1,…);
JOIN match records in streams/tables CREATE TABLE t AS SELECT * FROM l INNER JOIN r ON l.ID = r.ID;
KEY specify key column CREATE TABLE users (userId INT PRIMARY KEY, …
LEFT specify LEFT JOIN CREATE TABLE t AS SELECT * FROM l LEFT JOIN r ON l.ID = r.ID;
LIKE match pattern WHERE UCASE(gender)='FEMALE' AND LCASE (regionid) LIKE '%_6'
LIMIT number of records to output SELECT * FROM users EMIT CHANGES LIMIT 5;
LIST list objects LIST STREAMS; or SHOW STREAMS;
MAP map data type SELECT MAP(k1:=v1, k2:=v1*2) FROM s1 EMIT CHANGES;
MILLISECOND time unit of one ms for a window WINDOW TUMBLING (SIZE 1 MILLISECOND, RETENTION 1 DAY)
MILLISECONDS time unit of ms for a window WINDOW TUMBLING (SIZE 100 MILLISECONDS, RETENTION 1 DAY)
MINUTE time unit of one min for a window WINDOW TUMBLING (SIZE 1 MINUTE, RETENTION 1 DAY)
MINUTES time unit of mins for a window WINDOW TUMBLING (SIZE 30 MINUTES, RETENTION 1 DAY)
MONTH time unit of one month for a window WINDOW TUMBLING (SIZE 1 HOUR, RETENTION 1 MONTH)
MONTHS time unit of months for a window WINDOW TUMBLING (SIZE 1 HOUR, RETENTION 2 MONTHs)
NOT logical "not" operator
NULL field with no value CREATE STREAM s AS SELECT * FROM t WHERE (t.c1 IS NOT NULL);
ON specify join criteria LEFT JOIN users ON pageviews.userid = users.userid
OR logical "or" operator WHERE userid='User_1' OR userid='User_2'
OUTER specify OUTER JOIN CREATE TABLE t AS SELECT * FROM l FULL OUTER JOIN r ON l.ID = r.ID;
PARTITION BY repartition a stream PARTITION BY <key-field>
PARTITIONS partitions to distribute keys over CREATE STREAM users_rekeyed WITH (PARTITIONS=6) AS …
PERIOD grace period for a tumbling window WINDOW TUMBLING (SIZE 1 HOUR, GRACE PERIOD 2 HOURS)
PLUGINS show connector plugins LIST CONNECTOR PLUGINS; or SHOW CONNECTOR PLUGINS;
PRIMARY specify primary key column CREATE TABLE users (userId INT PRIMARY KEY, …
PRINT output records in a topic PRINT <topic-name> FROM BEGINNING;
PROPERTIES list all properties LIST PROPERTIES; or SHOW PROPERTIES;
QUERIES list all queries LIST QUERIES; or SHOW QUERIES;
REPLACE string replace REPLACE(col1, 'foo', 'bar')
RETENTION time to retain past windows WINDOW TUMBLING (SIZE 30 SECONDS, RETENTION 1000 DAYS)
RUN SCRIPT execute queries from a file RUN SCRIPT <path-to-query-file>;
SAMPLE number of messages to skip in PRINT PRINT <topic-name> SAMPLE 5;
SECOND time unit of one sec for a window WINDOW TUMBLING (SIZE 1 SECOND, RETENTION 1 DAY)
SECONDS time unit of secs for a window WINDOW TUMBLING (SIZE 30 SECONDS, RETENTION 1 DAY)
SELECT query a stream or table SELECT * FROM metrics EMIT CHANGES;
SESSION specify a session window WINDOW SESSION (60 SECONDS)
SET assign a property value SET 'auto.offset.reset'='earliest';
SHOW list objects SHOW FUNCTIONS;
SINK create a sink connector CREATE SINK CONNECTOR …
SIZE time length of a window WINDOW TUMBLING (SIZE 5 SECONDS)
SOURCE create a source connector CREATE SOURCE CONNECTOR …
STREAM register a stream on a topic CREATE STREAM users_orig AS SELECT * FROM users EMIT CHANGES;
STREAMS list all streams SHOW STREAMS;
STRUCT struct data type SELECT STRUCT(f1 := v1, f2 := v2) FROM s1 EMIT CHANGES;
TABLE register a table on a topic CREATE TABLE users (id BIGINT PRIMARY KEY, …
TABLES list all tables SHOW TABLES;
TERMINATE end a persistent query TERMINATE query_id;
THEN return expression in a CASE block CASE WHEN units<2 THEN 'sm' WHEN units<4 THEN 'med' ELSE 'large' …
TIME time data type
TIMESTAMP timestamp data type
TIMESTAMP specify a timestamp column CREATE STREAM pageviews WITH (TIMESTAMP='viewtime', …
TOPIC specify Kafka topic to delete DROP TABLE <table-name> DELETE TOPIC;
TOPICS list all streams LIST TOPICS; or SHOW TOPICS;
TRUE Boolean value of true
TUMBLING specify a tumbling window WINDOW TUMBLING (SIZE 5 SECONDS)
TYPE alias a complex type declaration CREATE TYPE <type_name> AS <type>;
TYPES list all custom type aliases LIST TYPES; or SHOW TYPES;
UNDEFINE undefine a variable UNDEFINE name;
UNSET unassign a property value UNSET 'auto.offset.reset';
VALUES list of values to insert INSERT INTO foo VALUES ('key', 'A');
VARIABLES list all variables LIST VARIABLES; or SHOW VARIABLES;
WHEN specify condition in a CASE block SELECT CASE WHEN condition THEN result [ WHEN … THEN … ] …
WHERE filter records by a condition SELECT * FROM pageviews WHERE pageid < 'Page_20'
WINDOW groups rows with the same keys SELECT userid, COUNT(*) FROM users WINDOW SESSION (60 SECONDS) …
WITH specify object creation params CREATE STREAM pageviews WITH (TIMESTAMP='viewtime', …
WITHIN time range in a windowed join SELECT * FROM impressions i JOIN clicks c WITHIN 1 minute …
YEAR time unit of one year for a window WINDOW TUMBLING (SIZE 1 HOUR, RETENTION 1 YEAR)
YEARS time unit of years for a window WINDOW TUMBLING (SIZE 1 HOUR, RETENTION 2 YEARS)

Operators

The following table shows all operators in the language.

operator meaning applies to
= is equal to string, numeric
!= or <> is not equal to string, numeric
< is less than string, numeric
<= is less than or equal to string, numeric
> is greater than string, numeric
>= is greater than or equal to string, numeric
+ addition for numeric, concatenation for string string, numeric
- subtraction numeric
* multiplication numeric
/ division numeric
% modulus numeric
|| or + concatenation string
:= assignment all
-> struct field dereference struct
. source dereference table, stream
=> lambda expression function
E or e exponent numeric
NOT logical NOT boolean
AND logical AND boolean
OR logical OR boolean
BETWEEN test if value within range numeric, string
LIKE match a pattern string
IN short hand for multiple OR expressions all
-- simple comment string
/* */ bracketed comment string
[email protected] directive comment string

Last update: 2022-01-19