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fc34b0d9de
Introduce a GUC and a tablespace option to control I/O prefetching, much like effective_io_concurrency, but for work that is done on behalf of many client sessions. Use the new setting in heapam.c instead of the hard-coded formula effective_io_concurrency + 10 introduced by commit 558a9165e08. Go with a default value of 10 for now, because it's a round number pretty close to the value used for that existing case. Discussion: https://postgr.es/m/CA%2BhUKGJUw08dPs_3EUcdO6M90GnjofPYrWp4YSLaBkgYwS-AqA%40mail.gmail.com
22 lines
672 B
C
22 lines
672 B
C
/*-------------------------------------------------------------------------
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*
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* spccache.h
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* Tablespace cache.
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*
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* Portions Copyright (c) 1996-2020, 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/utils/spccache.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef SPCCACHE_H
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#define SPCCACHE_H
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void get_tablespace_page_costs(Oid spcid, float8 *spc_random_page_cost,
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float8 *spc_seq_page_cost);
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int get_tablespace_io_concurrency(Oid spcid);
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int get_tablespace_maintenance_io_concurrency(Oid spcid);
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#endif /* SPCCACHE_H */
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