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Added page_range to records_in_range() to improve range statistics

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Prototype change:
-  virtual ha_rows records_in_range(uint inx, key_range *min_key,
-                                   key_range *max_key)
+  virtual ha_rows records_in_range(uint inx, const key_range *min_key,
+                                   const key_range *max_key,
+                                   page_range *res)

The handler can ignore the page_range parameter. In the case the handler
updates the parameter, the optimizer can deduce the following:
- If previous range's last key is on the same block as next range's first
  key
- If the current key range is in one block
- We can also assume that the first and last block read are cached!
  This can be used for a better calculation of IO seeks when we
  estimate the cost of a range index scan.

The parameter is fully implemented for MyISAM, Aria and InnoDB.
A separate patch will update handler::multi_range_read_info_const() to
take the benefits of this change and also remove the double
records_in_range() calls that are not anymore needed.
This commit is contained in:
Monty
2020-02-27 19:12:27 +02:00
parent 9b06199080
commit f36ca142f7
63 changed files with 333 additions and 188 deletions
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10
storage/sequence/sequence.cc
View File

@@ -93,9 +93,8 @@ public:
int index_prev(uchar *buf);
int index_first(uchar *buf);
int index_last(uchar *buf);
ha_rows records_in_range(uint inx, key_range *min_key,
key_range *max_key);
ha_rows records_in_range(uint inx, const key_range *start_key,
const key_range *end_key, page_range *pages);
double scan_time() { return (double)nvalues(); }
double read_time(uint index, uint ranges, ha_rows rows) { return (double)rows; }
double keyread_time(uint index, uint ranges, ha_rows rows) { return (double)rows; }
@@ -234,8 +233,9 @@ int ha_seq::index_last(uchar *buf)
return index_prev(buf);
}
ha_rows ha_seq::records_in_range(uint inx, key_range *min_key,
key_range *max_key)
ha_rows ha_seq::records_in_range(uint inx, const key_range *min_key,
const key_range *max_key,
page_range *pages)
{
ulonglong kmin= min_key ? uint8korr(min_key->key) : seqs->from;
ulonglong kmax= max_key ? uint8korr(max_key->key) : seqs->to - 1;