hyoungjunkim created TAJO-482:
---------------------------------
Summary: Implements listing functions and describing a specified
function.
Key: TAJO-482
URL: https://issues.apache.org/jira/browse/TAJO-482
Project: Tajo
Issue Type: Sub-task
Reporter: hyoungjunkim
Priority: Minor
I propose function related commands in Tajo's shell. This command is similar to
PostgreSQL but a little different.
- \df: list all functions
- \df <function name>: list all functions which have a specified
name(PostgreSQL uses a pattern matching).
{code}
tajo> \df
List of functions
Name | Result data type | Argument data types | Type
-----+------------------+---------------------+-------------
avg | FLOAT8 | INT8 | AGGREGATION
sum | INT8 | INT8 | AGGREGATION
sum | INT4 | INT4 | AGGREGATION
sum | FLOAT4 | FLOAT4 | AGGREGATION
...
(80 rows)
tajo> \df sum
List of functions
Name | Result data type | Argument data types | Type
-----+------------------+---------------------+-------------
sum | INT8 | INT8 | AGGREGATION
sum | INT4 | INT4 | AGGREGATION
sum | FLOAT4 | FLOAT4 | AGGREGATION
(3 rows)
Function: INT8 sum(expr INT8)
Description: The sum of a set of numbers.
Example:
> select sum(*)
{code}
When describing a specified function
if all functions have same description, prints out first function description.
Otherwise prints out all function.
{code}
tajo> \df to_char
List of functions
Name | Result data type | Argument data types | Type
--------+-------------------+---------------------+-------------
to_char | TEXT | TIMETSTAMP, TEXT | GENERAL
to_char | TEXT | INT4 | GENERAL
(2 rows)
Function: TEXT to_char(timestamp TIMETSTAMP, pattern TEXT)
Description: convert time stamp to string.
Example:
> select to_char(current_timestamp, 'HH12:MI:SS');
11:34:52
Function: TEXT to_char(pattern INT4)
Description: convert time stamp to string.
Example:
> select to_char(25, '000');
025
{code}
--
This message was sent by Atlassian JIRA
(v6.1.5#6160)
