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2e4127b6d2
This commit introduces a new CopyToRoutine struct, which is a set of callback routines to copy tuples in a specific format. It also makes the existing formats (text, CSV, and binary) utilize these format callbacks. This change is a preliminary step towards making the COPY TO command extensible in terms of output formats. Additionally, this refactoring contributes to a performance improvement by reducing the number of "if" branches that need to be checked on a per-row basis when sending field representations in text or CSV mode. The performance benchmark results showed ~5% performance gain in text or CSV mode. Author: Sutou Kouhei <kou@clear-code.com> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com> Reviewed-by: Junwang Zhao <zhjwpku@gmail.com> Discussion: https://postgr.es/m/20231204.153548.2126325458835528809.kou@clear-code.com
58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
/*-------------------------------------------------------------------------
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*
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* copyapi.h
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* API for COPY TO handlers
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*
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*
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* Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/commands/copyapi.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef COPYAPI_H
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#define COPYAPI_H
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#include "commands/copy.h"
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/*
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* API structure for a COPY TO format implementation. Note this must be
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* allocated in a server-lifetime manner, typically as a static const struct.
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*/
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typedef struct CopyToRoutine
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{
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/*
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* Set output function information. This callback is called once at the
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* beginning of COPY TO.
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*
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* 'finfo' can be optionally filled to provide the catalog information of
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* the output function.
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*
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* 'atttypid' is the OID of data type used by the relation's attribute.
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*/
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void (*CopyToOutFunc) (CopyToState cstate, Oid atttypid,
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FmgrInfo *finfo);
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/*
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* Start a COPY TO. This callback is called once at the beginning of COPY
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* TO.
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*
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* 'tupDesc' is the tuple descriptor of the relation from where the data
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* is read.
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*/
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void (*CopyToStart) (CopyToState cstate, TupleDesc tupDesc);
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/*
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* Write one row stored in 'slot' to the destination.
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*/
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void (*CopyToOneRow) (CopyToState cstate, TupleTableSlot *slot);
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/*
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* End a COPY TO. This callback is called once at the end of COPY TO.
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*/
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void (*CopyToEnd) (CopyToState cstate);
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} CopyToRoutine;
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#endif /* COPYAPI_H */
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