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[PATCH] Add missing type conversion functions for PL/Python - Mailing list pgsql-hackers

From	Haozhou Wang
Subject	[PATCH] Add missing type conversion functions for PL/Python
Date	January 31, 2018 09:57:12
Msg-id	CAL_NLpKXMwv2ewZbtvUzujZxMgUq++6TgNTFRnY4+Tcsx7+1GQ@mail.gmail.com Whole thread Raw
Responses	Re: [PATCH] Add missing type conversion functions for PL/Python
List	pgsql-hackers

Hi All,

PL/Python already has different type conversion functions to

convert PostgreSQL datum to Python object. However, the conversion

functions from Python object to PostgreSQL datum only has Boolean,

Bytea and String functions.

In this patch, we add rest of Integer and Float related datatype conversion functions

and can increase the performance of data conversion greatly especially

when returning a large array.

We did a quick test about the performance of returning array in PL/Python:

The following UDF is used for test:

```

CREATE OR REPLACE FUNCTION pyoutfloat8(num int) RETURNS float8[] AS $$ return [x/3.0 for x in range(num)]

$$ LANGUAGE plpythonu;

```

The test command is

```

select count(pyoutfloat8(n));

```

The count is used for avoid large output, where n is the number of element in returned array, and the size is from 1.5k to15m.

Size of Array 1.5k | 15k | 150k | 1.5m | 15m |

Origin 2.324ms | 19.834ms | 194.991ms | 1927.28ms | 19982.1ms |

With this patch 1.168ms | 3.052ms | 21.888ms | 213.39ms | 2138.5ms |

All test for both PG and PL/Python are passed.

Thanks very much.

Regards,

Haozhou

From: Amit Kapila
Date: 31 January 2018, 09:29:31
Subject: Re: Wait for parallel workers to attach

From: Kyotaro HORIGUCHI
Date: 31 January 2018, 10:09:09
Subject: Re: [HACKERS] [PATCH] Improve geometric types