DESCRIBE statement in ksqlDB for Confluent Platform

Synopsis

DESCRIBE (stream_name|table_name|STREAMS|TABLES) [EXTENDED];

Description

• DESCRIBE: List the columns in a stream or table along with their data type and other attributes, or list the relevant details for all streams and tables.
• DESCRIBE EXTENDED: Display DESCRIBE information with additional runtime statistics, Kafka topic details, and the set of queries that populate the table or stream.

Extended descriptions provide the following metrics for the topic backing the source being described.

ksqlDB Metric	Description
consumer-fa iled-messag es	Total number of failures during message consumption on the server.
consumer-me ssages-per- sec	The number of messages consumed per second from the topic by the server.
consumer-to tal-message -bytes	Total number of bytes consumed from the topic by the server.
consumer-to tal-message s	Total number of messages consumed from the topic by the server.
failed-mess ages-per-se c	Number of failures during message consumption (for example, deserialization failures) per second on the server.
last-failed	Time that the last failure occurred when a message was consumed from the topic by the server.
last-messag e	Time that the last message was produced to or consumed from the topic by the server.
messages-pe r-sec	Number of messages produced per second into the topic by the server.
total-messa ges	Total number of messages produced into the topic by the server.
total-messa ge-bytes	Total number of bytes produced into the topic by the server.

Example

The following statement shows how to get a description of a table.

DESCRIBE ip_sum;

Your output should resemble:

 Field   | Type
-----------------------------------------
 IP      | VARCHAR(STRING)  (primary key)
 KBYTES  | BIGINT
-----------------------------------------
For runtime statistics and query details run: DESCRIBE <Stream,Table> EXTENDED

The following statement shows how to get a description of a table that has extended information.

DESCRIBE ip_sum EXTENDED;

Your output should resemble:

Type                 : TABLE
Timestamp field      : Not set - using <ROWTIME>
Key format           : KAFKA
Value format         : JSON
Kafka output topic   : IP_SUM (partitions: 4, replication: 1)

 Field   | Type
-----------------------------------------
 IP      | VARCHAR(STRING)  (primary key)
 KBYTES  | BIGINT
-----------------------------------------

Queries that write into this TABLE
-----------------------------------
id:CTAS_IP_SUM - CREATE TABLE IP_SUM as SELECT ip,  sum(bytes)/1024 as kbytes FROM CLICKSTREAM window SESSION (300 second) GROUP BY ip EMIT CHANGES;

For query topology and execution plan run: EXPLAIN <QueryId>; for more information

Local runtime statistics
------------------------
messages-per-sec:      4.41   total-messages:       486     last-message: 12/14/17 4:32:23 PM GMT
  failed-messages:         0      last-failed:       n/a
(Statistics of the local ksqlDB server interaction with the Kafka topic IP_SUM)

The following statement shows how to get the descriptions for all tables.

DESCRIBE TABLES;

Your output should resemble:

Name                 : IP_SUM
 Field   | Type
-----------------------------------------
 IP      | VARCHAR(STRING)  (primary key)
 KBYTES  | BIGINT
-----------------------------------------
For runtime statistics and query details run: DESCRIBE <Stream,Table> EXTENDED;
Name                 : LO_REM

 Field   | Type
-----------------------------------------
 LO      | VARCHAR(STRING)  (primary key)
 KBYTES  | BIGINT
-----------------------------------------
For runtime statistics and query details run: DESCRIBE <Stream,Table> EXTENDED;

The following statement shows how to get the descriptions for all tables with extended information.

DESCRIBE TABLES EXTENDED;

Your output should resemble:

Name                 : IP_SUM
Type                 : TABLE
Timestamp field      : Not set - using <ROWTIME>
Key format           : KAFKA
Value format         : JSON
Kafka output topic   : IP_SUM (partitions: 4, replication: 1)
Statement            : CREATE TABLE IP_SUM as SELECT ip,  sum(bytes)/1024 as kbytes FROM CLICKSTREAM window SESSION (300 second) GROUP BY ip EMIT CHANGES;

 Field   | Type
-----------------------------------------
 IP      | VARCHAR(STRING)  (primary key)
 KBYTES  | BIGINT
-----------------------------------------

Queries that write into this TABLE
-----------------------------------
id:CTAS_IP_SUM - CREATE TABLE IP_SUM as SELECT ip,  sum(bytes)/1024 as kbytes FROM CLICKSTREAM window SESSION (300 second) GROUP BY ip EMIT CHANGES;

For query topology and execution plan run: EXPLAIN <QueryId>; for more information

Local runtime statistics
------------------------
messages-per-sec:      4.41   total-messages:       486     last-message: 12/14/17 4:32:23 PM GMT
  failed-messages:         0      last-failed:       n/a
(Statistics of the local ksqlDB server interaction with the Kafka topic IP_SUM)

Name                 : LO_REM
Type                 : TABLE
Timestamp field      : Not set - using <ROWTIME>
Key format           : KAFKA
Value format         : JSON
Kafka output topic   : LO_REM (partitions: 4, replication: 1)
Statement            : CREATE TABLE LO_REM as SELECT lo,  sum(bytes)/1024 as kbytes FROM CLICKSTREAM window SESSION (300 second) GROUP BY ip EMIT CHANGES;

 Field   | Type
-----------------------------------------
 LO      | VARCHAR(STRING)  (primary key)
 KBYTES  | BIGINT
-----------------------------------------

Queries that write into this TABLE
-----------------------------------
id:CTAS_LO_REM - CREATE TABLE LO_REM as SELECT lo,  sum(bytes)/1024 as kbytes FROM CLICKSTREAM window SESSION (300 second) GROUP BY ip EMIT CHANGES;

For query topology and execution plan run: EXPLAIN <QueryId>; for more information

Local runtime statistics
------------------------
messages-per-sec:      4.41   total-messages:       486     last-message: 12/14/17 4:32:23 PM GMT
  failed-messages:         0      last-failed:       n/a
(Statistics of the local ksqlDB server interaction with the Kafka topic LO_REM)