Re: [Patch proposal] libpq portal support - Mailing list pgsql-hackers

From Sergei Fedorov
Subject Re: [Patch proposal] libpq portal support
Date
Msg-id CAENDX4KxFRxKDFb+U8jApW7=zRSHsLFhTNKtTrwQGhJ7QCkSww@mail.gmail.com
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In response to Re: [Patch proposal] libpq portal support  (Craig Ringer <craig@2ndquadrant.com>)
Responses Re: [Patch proposal] libpq portal support  (Craig Ringer <craig@2ndquadrant.com>)
Re: [Patch proposal] libpq portal support  (Craig Ringer <craig@2ndquadrant.com>)
List pgsql-hackers
Hello everybody,

Yes, we will be happy to put our patch under the PostgreSQL License.

Patch is attached to this email, master was rebased to head prior to creating the patch.

We are using a C++ wrapper on top of libpq for using database connections in multithreaded asynchronous applications. For security reasons (and partially because we are too lazy to escape query parameters) we use prepared queries and parameter binding for execution. There are situations when we need to fetch the query results not in one batch but in a `paged` way, the most convenient way is to use the portals feature of PosgreSQL protocol.

пт, 18 окт. 2019 г. в 15:21, Craig Ringer <craig@2ndquadrant.com>:
On Thu, 17 Oct 2019 at 03:12, Sergei Fedorov <sergei.a.fedorov@gmail.com> wrote:
Hello everybody,

Our company was in desperate need of portals in async interface of libpq, so we patched it.

We would be happy to upstream the changes.

The description of changes:

Two functions in libpq-fe.h:
PQsendPortalBindParams for sending a command to bind a portal to a previously prepared statement;
PQsendPortalExecute for executing a previously bound portal with a given number of rows.

A patch to pqParseInput3 in fe-protocol3.c to handle the `portal suspended` message tag.

The patch is ready for review, but it lacks documentation, tests and usage examples.

There are no functions for sending bind without params and no functions for sync interface, but they can easily be added to the feature.

If you are happy to put it under The PostgreSQL License, then sending it as an attachment here is the first step.

If possible, please rebase it on top of git master.

Some explanation for why you have this need and what problems this solves for you would be helpful as well.

--
 Craig Ringer                   http://www.2ndQuadrant.com/
 2ndQuadrant - PostgreSQL Solutions for the Enterprise


--
Thank you,
Sergei Fedorov
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