WT-2366 Extend wtperf to support changing record sizes in update ops

Via a new update_delta setting in the thread group which takes either
a signed number of "rand" as an argument. Defaults to 0 (disabled).

There is also a new value_sz_max configuration option to limit how
large values can grow.

1 files changed, 6 insertions, 3 deletions

diff --git a/src/docs/wtperf.dox b/src/docs/wtperf.dox
index 6f3d2f87ee0..59176f7909a 100644
--- a/src/docs/wtperf.dox
+++ b/src/docs/wtperf.dox
@@ -251,14 +251,17 @@ threads configuration might be
 'threads=((count=2,reads=1)(count=8,reads=1,inserts=2,updates=1))'
 which would create 2 threads doing nothing but reads and 8 threads
 each doing 50% inserts and 25% reads and updates.  Allowed
-configuration values are 'count', 'throttle', 'reads', 'inserts',
-'updates', 'truncate', 'truncate_pct' and 'truncate_count'. There are
-also behavior modifiers, supported modifiers are 'ops_per_txn'
+configuration values are 'count', 'throttle', 'update_delta', 'reads',
+'inserts', 'updates', 'truncate', 'truncate_pct' and 'truncate_count'.
+There are also behavior modifiers, supported modifiers are
+'ops_per_txn'
 @par transaction_config (string, default=)
 transaction configuration string, relevant when populate_opts_per_txn
 is nonzero
 @par table_name (string, default=test)
 table name
+@par value_sz_max (unsigned int, default=1000)
+maximum value size when delta updates are present. Default disabled
 @par value_sz (unsigned int, default=100)
 value size
 @par verbose (unsigned int, default=1)