WL#7339 started to use more correct records per key estimates from
InnoDB. This caused the cost estimate for the original query plan
to become four times higher than previous, which caused another
query plan to be selected.

The new selected query plan does a table scan on the orders table.
This table has 1.5 million records. On this table we have the
following condition:

  orders.o_orderstatus = 'F'

This is used for calculating the condition filter effect for this
table. With the current guestimate for equality conditions of 0.005,
this caused the estimated number of partial rows to be produced from
this table to be only 7500. In reality, 730.000 rows were produced.

The cause for this very wrong estimate is that the o_orderstatus
column only contains three distinct values and almost half of the
records have the value 'F'.

To make the condition filter produce a better (more conservative)
estimate for cases like this and to reduce the likelihood of
similar regressions, the fix for this problem is to increase the
condition filter constant for equality estimates to 0.1. With this
we estimate that 1 of 10 records will pass the filter (instead of
only 1 out of 200).

Changes in tests:

@ mysql-test/r/compress.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/derived.result
   Mostly changes to filtered estimates. One change in query plan.
   This query now gets the same plan as it had before WL#6635.
@ mysql-test/r/ds_mrr-big.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/eq_range_idx_stat.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/explain_for_connection_rqg_json.result
   Mostly changes to filtered and rows estimates. One
   query has changes to its query plan.
@ mysql-test/r/explain_for_connection_rqg_trad.result
   Mostly changes to filtered and rows estimates. One
   query has changes to its query plan.
@ mysql-test/r/explain_other.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/filter_single_col_idx_big.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/filter_single_col_idx_small.result
   Mostly changes to filtered estimates. One query has
   changes to its query plan: changes from using FirstMatch
   to do materialization.
@ mysql-test/t/filter_single_col_idx_small.test
   Added test to verify that the filter estimate for basic
   filter constants is not less than one row
@ mysql-test/r/greedy_optimizer.result
   Mostly changes to filtered and cost estimates. Eight queries
   has changes in query plans. Four of these changes back to
   the query plan they had before WL#6335 was pushed. The four
   last had similar changes in query plans as for when WL#6635 was
   pushed.
@ mysql-test/r/greedy_search.result
   Mostly changes to filtered estimates. Two queries has
   changes to its query plan. One of these are returned to
   what it was before WL#6635 was pushed. The other has
   similar changes to as what was introduced by WL#6335.
   The number of partial query plans for some queries are
   increased. With the exception of one of these, all
   new numbers are below what it was before WL#6335.
   The one the has a very high increas in the number of
   partial query plans, changes from 22201 to 5799004.
   Before WL#6635 this query considered 735518 partial
   query plans.
@ mysql-test/r/group_by.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/group_min_max.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/group_min_max_innodb.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/heap.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/heap_hash.result
   One change in query plan. The new plan is more similar
   to what the query plan was before WL#6635 was pushed. It has
   the same join order but uses table scan on the second
   table instead of ref access as it did before WL#6635.
@ mysql-test/r/index_merge_innodb.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/index_merge_intersect_dml.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/index_merge_myisam.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/innodb_explain_json_non_select_all.result
   Changes in filtered, rows and cost estimates in explain output.
@ mysql-test/r/innodb_explain_json_non_select_none.result
   Changes in filtered, rows and estimates in explain output.
@ mysql-test/r/innodb_explain_non_select_all.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/innodb_explain_non_select_none.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/innodb_icp.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/innodb_icp_all.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/innodb_icp_none.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join_cache_bka.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join_cache_bka_nixbnl.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join_cache_bkaunique.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join_cache_bnl.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join_cache_nojb.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join_outer.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join_outer_bka.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/join_outer_bka_nixbnl.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/myisam_explain_json_non_select_all.result
   Changes in filtered, rows and cost estimates in explain output.
@ mysql-test/r/myisam_explain_json_non_select_none.result
   Changes in filtered, rows and cost estimates in explain output.
@ mysql-test/r/myisam_explain_non_select_all.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/myisam_explain_non_select_none.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/myisam_icp.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/myisam_icp_all.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/myisam_icp_none.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/named_pipe.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/negation_elimination.result
   Changes in filtered estimate in explain output.
@ mysql-test/r/null_key_all.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/null_key_icp.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/null_key_none.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/order_by_all.result
  One query has changes to query plan. The new query plan
  is the same as this query had before WL#6635 was pushed.
@ mysql-test/r/order_by_icp_mrr.result
  One query has changes to query plan. The new query plan
  is the same as this query had before WL#6635 was pushed.
@ mysql-test/r/order_by_none.result
  One query has changes to query plan. The new query plan
  is the same as this query had before WL#6635 was pushed.
@ mysql-test/r/partition_locking.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/partition_pruning.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/range_all.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/range_icp.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/range_icp_mrr.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/range_mrr.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/range_mrr_cost.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/range_none.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_all.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_all_bka.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_all_bka_nixbnl.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_icp_mrr.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_icp_mrr_bka.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_icp_mrr_bka_nixbnl.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_none.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_none_bka.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/select_none_bka_nixbnl.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/shm.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/ssl.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/ssl_compress.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_all.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_all_bka.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_all_bka_nixbnl.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_nomat_nosj.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_nomat_nosj_bka.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_nomat_nosj_bka_nixbnl.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_none.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_none_bka.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_none_bka_nixbnl.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/subquery_sj_all.result
  Mostly changes to filtered, rows and cost estimates. Three queries
  has plan changes. Two of these returns to what the plan was before
  WL#6635. The last has changes that makes the plan look more like
  it was before WL#6635 but not identical.
@ mysql-test/r/subquery_sj_all_bka.result
  Mostly changes to filtered, rows and cost estimates. Seven
  queries have real plan changes. Four of these returns to
  the plan they had before WL#6635.
@ mysql-test/r/subquery_sj_all_bka_nixbnl.result
  Mostly changes to filtered, rows and cost estimates. Seven
  queries have real plan changes. Four of these returns to
  the plan they had before WL#6635.
@ mysql-test/r/subquery_sj_all_bkaunique.result
  Mostly changes to filtered, rows and cost estimates. Eight
  queries have real plan changes. Five of these returns to
  the plan they had before WL#6635.
@ mysql-test/r/subquery_sj_dupsweed.result
  Mostly changes to filtered, rows and cost estimates. One
  query has real plan changes. The new query plan is the
  same as this query had before WL#6635.
@ mysql-test/r/subquery_sj_dupsweed_bka.result
  Mostly changes to filtered, rows and cost estimates. Two
  queries have real plan changes. The new query plans are the
  same as these queries had before WL#6635.
@ mysql-test/r/subquery_sj_dupsweed_bka_nixbnl.result
  Changes to filtered, rows and cost estimates.
@ mysql-test/r/subquery_sj_dupsweed_bkaunique.result
  Mostly changes to filtered, rows and cost estimates. Two
  queries have real plan changes. The new query plans are the
  same as these queries had before WL#6635.
@ mysql-test/r/subquery_sj_firstmatch.result
  Mostly changes to filtered, rows and cost estimates. One
  query has real plan changes. The new query plan is the
  same as this query had before WL#6635.
@ mysql-test/r/subquery_sj_firstmatch_bka.result
  Mostly changes to filtered, rows and cost estimates. One
  query has real plan changes. The new query plan is the
  same as this query had before WL#6635.
@ mysql-test/r/subquery_sj_firstmatch_bka_nixbnl.result
  Changes to filtered, rows and cost estimates.
@ mysql-test/r/subquery_sj_firstmatch_bkaunique.result
  Mostly changes to filtered, rows and cost estimates. One
  query has real plan changes. The new query plan is the
  same as this query had before WL#6635.
@ mysql-test/r/subquery_sj_loosescan.result
  Mostly changes to filtered, rows and cost estimates. Four
  queries have real plan changes. The new query plans are the
  same as these queries had before WL#6635.
@ mysql-test/r/subquery_sj_loosescan_bka.result
  Mostly changes to filtered, rows and cost estimates. Four
  queries have real plan changes. The new query plans are the
  same as these queries had before WL#6635.
@ mysql-test/r/subquery_sj_loosescan_bka_nixbnl.result
  Mostly changes to filtered, rows and cost estimates. Two
  queries have real plan changes. The new query plans are the
  same as these queries had before WL#6635.
@ mysql-test/r/subquery_sj_loosescan_bkaunique.result
  Mostly changes to filtered, rows and cost estimates. Four
  queries have real plan changes. The new query plans are the
  same as these queries had before WL#6635.
@ mysql-test/r/subquery_sj_mat.result
  Mostly changes to filtered, rows and cost estimates. Eight
  queries have real plan changes. Seven of these returns to
  the plan they had before WL#6635.
@ mysql-test/r/subquery_sj_mat_bka.result
  Mostly changes to filtered, rows and cost estimates. Eight
  queries have real plan changes. Seven of these returns to
  the plan they had before WL#6635.
@ mysql-test/r/subquery_sj_mat_bka_nixbnl.result
  Mostly changes to filtered, rows and cost estimates. Seven
  queries have real plan changes. Six of these returns to
  the plan they had before WL#6635.
@ mysql-test/r/subquery_sj_mat_bkaunique.result
  Mostly changes to filtered, rows and cost estimates. Eight
  queries have real plan changes. Seven of these returns to
  the plan they had before WL#6635.
@ mysql-test/r/subquery_sj_mat_nosj.result
  Changes to filtered and cost estimates in explain output.
@ mysql-test/r/subquery_sj_none.result
  Changes to filtered, rows and cost estimates in explain output.
@ mysql-test/r/subquery_sj_none_bka.result
  Changes to filtered, rows and cost estimates in explain output.
@ mysql-test/r/subquery_sj_none_bka_nixbnl.result
  Changes to filtered, rows and cost estimates in explain output.
@ mysql-test/r/subquery_sj_none_bkaunique.result
  Changes to filtered, rows and cost estimates in explain output.
@ mysql-test/r/subselect_innodb.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/type_temporal_fractional.result
  Changes in filtered estimate in explain output.
@ mysql-test/r/wl6711_heap_to_disk.result
  Changes in filtered estimate in explain output.
@ mysql-test/suite/innodb/r/innodb_lock_wait_timeout_1.result
  Changes in filtered estimate in explain output.
@ mysql-test/suite/opt_trace/r/general2_no_prot.result
  Changes in rows and cost estimates in explain output.
@ mysql-test/suite/opt_trace/r/general2_ps_prot.result
  Changes in rows and cost estimates in explain output.
@ mysql-test/suite/opt_trace/r/range_no_prot.result
  Changes in filtered and rows estimates in explain output.
@ mysql-test/suite/opt_trace/r/range_ps_prot.result
  Changes in filtered estimate in explain output.
@ mysql-test/suite/opt_trace/r/subquery_no_prot.result
  Changes in filtered, rows and cost estimates in explain output.
@ mysql-test/suite/opt_trace/r/subquery_ps_prot.result
  Changes in filtered, rows and cost estimates in explain output.
@ mysql-test/suite/parts/r/partition_alter3_innodb.result
  Changes in filtered estimate in explain output.
@ mysql-test/suite/parts/r/partition_alter3_myisam.result
  Changes in filtered estimate in explain output.
@ mysql-test/suite/perfschema/r/batch_table_io_func.result
  Changes in filtered estimate in explain output.
@ sql/item.h
  Change the value for the condition filter constant COND_FILTER_EQUALITY
  from 0.005 to 0.1.
@ unittest/gunit/item_filter-t.cc
  Change in unit test for condition filter for IN lists:
  Reduced from having six values in the IN list to four
  values. The reason is that with six values in the
  IN list the calculated condition filter will be larger
  than 0.5 and then rounded down to 0.5.