The default settings enable checksum verification on every read.

Summary: The default settings enable checksum verification on every read.

Test Plan: make check

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15591

Author: dhruba

db/version_set.cc

@@ -2088,7 +2088,6 @@ Compaction* VersionSet::CompactRange(int input_level, int output_level,
 
 Iterator* VersionSet::MakeInputIterator(Compaction* c) {
   ReadOptions options;
-  options.verify_checksums = options_->paranoid_checks;
   options.fill_cache = false;
 
   // Level-0 files have to be merged together.  For other levels,

include/rocksdb/options.h

@@ -672,7 +672,7 @@ enum ReadTier {
 struct ReadOptions {
   // If true, all data read from underlying storage will be
   // verified against corresponding checksums.
-  // Default: false
+  // Default: true
   bool verify_checksums;
 
   // Should the "data block"/"index block"/"filter block" read for this
@@ -713,11 +713,13 @@ struct ReadOptions {
 
   // Specify to create a tailing iterator -- a special iterator that has a
   // view of the complete database (i.e. it can also be used to read newly
-  // added data) and is optimized for sequential reads.
+  // added data) and is optimized for sequential reads. It will return records
+  // that were inserted into the database after the creation of the iterator.
+  // Default: false
   bool tailing;
 
   ReadOptions()
-      : verify_checksums(false),
+      : verify_checksums(true),
         fill_cache(true),
         prefix_seek(false),
         snapshot(nullptr),