DESCRIBE
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-failed-messages |
Total number of failures during message consumption on the server. |
| consumer-messages-per-sec |
The number of messages consumed per second from the topic by the server. |
| consumer-total-message-bytes |
Total number of bytes consumed from the topic by the server. |
| consumer-total-messages |
Total number of messages consumed from the topic by the server. |
| failed-messages-per-sec |
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-message |
Time that the last message was produced to or consumed from the topic by the server. |
| messages-per-sec |
Number of messages produced per second into the topic by the server. |
| total-messages |
Total number of messages produced into the topic by the server. |
| total-message-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.
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;
|
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23 | 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)
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The following statement shows how to get the descriptions for all tables.
Your output should resemble:
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15 | 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;
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51 | 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)
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Last update:
2021-03-12