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Code Issues

Moved page-level code to DPM.

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This commit is contained in:
dimitr 2005-03-29 09:43:31 +00:00
parent ac1d34cfcb
commit fde48e9530
3 changed files with 63 additions and 38 deletions
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38
src/jrd/Optimizer.cpp
View File

@ -590,43 +590,7 @@ double getRelationCardinality(thread_db* tdbb, jrd_rel* relation, const Format*
return (double) 10000;
}
else {
// Estimated number of total records for this relation,
// we assume that the records are compressed to 50%
// Every record has also a header and a jump section (13 + 4)
USHORT minRecordSize = sizeof(Ods::data_page::dpg_repeat) + RHD_SIZE;
if (!(dbb->dbb_flags & DBB_no_reserve)) {
minRecordSize += RHDF_SIZE;
}
// Get the number of data-pages for this relation
SLONG dataPages = DPM_data_pages(tdbb, relation);
// AB: If we have only 1 data-page then the cardinality calculation
// is to worse to be usefull, therefore rely on the record count
// from the data-page.
if (dataPages == 1) {
// AB: I'm not sure if this code really belongs here, may be
// a better place is dpm.cpp
vcl* vector = relation->rel_pages;
if (vector) {
WIN window(-1);
window.win_page = (*vector)[0];
Ods::pointer_page* ppage =
(Ods::pointer_page*) CCH_FETCH(tdbb, &window, LCK_read, pag_pointer);
SLONG record_count = 0;
const SLONG* page = ppage->ppg_page;
if (*page) {
Ods::data_page* dpage =
(Ods::data_page*) CCH_HANDOFF(tdbb, &window, *page, LCK_read, pag_data);
record_count = dpage->dpg_count;
}
CCH_RELEASE(tdbb, &window);
return record_count;
}
}
return (double) dataPages * (dbb->dbb_page_size - DPG_SIZE) /
(minRecordSize + (format->fmt_length * 0.5));
return DPM_cardinality(tdbb, relation, format);
}
}

60
src/jrd/dpm.epp
View File

@ -189,6 +189,66 @@ void DPM_backout( thread_db* tdbb, record_param* rpb)
}
double DPM_cardinality(thread_db* tdbb, jrd_rel* relation, const Format* format)
{
/**************************************
*
* D P M _ c a r d i n a l i t y
*
**************************************
*
* Functional description
* Estimate cardinality for the given relation.
*
**************************************/
SET_TDBB(tdbb);
Database* dbb = tdbb->tdbb_database;
// Estimated number of total records for this relation,
// we assume that the records are compressed to 50%
// Every record has also a header and a jump section (13 + 4)
USHORT minRecordSize = sizeof(Ods::data_page::dpg_repeat) + RHD_SIZE;
if (!(dbb->dbb_flags & DBB_no_reserve)) {
minRecordSize += RHDF_SIZE;
}
// Get the number of data-pages for this relation
SLONG dataPages = DPM_data_pages(tdbb, relation);
// AB: If we have only 1 data-page then the cardinality calculation
// is to worse to be usefull, therefore rely on the record count
// from the data-page.
if (dataPages == 1) {
vcl* vector = relation->rel_pages;
if (vector) {
WIN window(-1);
window.win_page = (*vector)[0];
Ods::pointer_page* ppage =
(Ods::pointer_page*) CCH_FETCH(tdbb, &window, LCK_read, pag_pointer);
USHORT recordCount = 0;
const SLONG* page = ppage->ppg_page;
if (*page) {
Ods::data_page* dpage =
(Ods::data_page*) CCH_HANDOFF(tdbb, &window, *page, LCK_read, pag_data);
recordCount = dpage->dpg_count;
}
CCH_RELEASE(tdbb, &window);
return (double) recordCount;
}
}
if (!format) {
format = relation->rel_current_format;
}
return (double) dataPages * (dbb->dbb_page_size - DPG_SIZE) /
(minRecordSize + (format->fmt_length * 0.5));
}
bool DPM_chain( thread_db* tdbb, record_param* org_rpb, record_param* new_rpb)
{
/**************************************

3
src/jrd/dpm_proto.h
View File

@ -43,7 +43,8 @@ namespace Ods {
Ods::pag* DPM_allocate(Jrd::thread_db*, Jrd::win*);
void DPM_backout(Jrd::thread_db*, Jrd::record_param*);
bool DPM_chain(Jrd::thread_db*, Jrd::record_param*, Jrd::record_param*);
double DPM_cardinality(Jrd::thread_db*, Jrd::jrd_rel*, const Jrd::Format*);
bool DPM_chain(Jrd::thread_db*, Jrd::record_param*, Jrd::record_param*);
int DPM_compress(Jrd::thread_db*, Ods::data_page*);
void DPM_create_relation(Jrd::thread_db*, Jrd::jrd_rel*);
SLONG DPM_data_pages(Jrd::thread_db*, Jrd::jrd_rel*);