[config](inverted index)Make inverted_index_ram_dir enable by default (…

…apache#35094)

`inverted_index_ram_dir_enable` can reduce disk IO in writing index time.
We turn it on by default.

Co-authored-by: Luennng <[email protected]>

be/src/common/config.cpp

@@ -1039,7 +1039,7 @@ DEFINE_mBool(inverted_index_compaction_enable, "true");
 // Only for debug, do not use in production
 DEFINE_mBool(debug_inverted_index_compaction, "false");
 // index by RAM directory
-DEFINE_mBool(inverted_index_ram_dir_enable, "false");
+DEFINE_mBool(inverted_index_ram_dir_enable, "true");
 // use num_broadcast_buffer blocks as buffer to do broadcast
 DEFINE_Int32(num_broadcast_buffer, "32");