diff --git a/table/block_based_table_reader.cc b/table/block_based_table_reader.cc index 7133dcf56800a70e7e82bfa5a789c5b85f5fb17a..bf0fc66137d19519c9b405d3de0b94c1b2744e25 100644 --- a/table/block_based_table_reader.cc +++ b/table/block_based_table_reader.cc @@ -738,8 +738,17 @@ Status BlockBasedTable::Open(const ImmutableCFOptions& ioptions, std::unique_ptr prefetch_buffer; - // Before read footer, readahead backwards to prefetch data - const size_t kTailPrefetchSize = 512 * 1024; + // prefetch both index and filters, down to all partitions + const bool prefetch_all = prefetch_index_and_filter_in_cache || level == 0; + const bool preload_all = !table_options.cache_index_and_filter_blocks; + // Before read footer, readahead backwards to prefetch data. Do more readahead + // if we're going to read index/filter. + // TODO: This may incorrectly select small readahead in case partitioned + // index/filter is enabled and top-level partition pinning is enabled. That's + // because we need to issue readahead before we read the properties, at which + // point we don't yet know the index type. + const size_t kTailPrefetchSize = + prefetch_all || preload_all ? 512 * 1024 : 4 * 1024; size_t prefetch_off; size_t prefetch_len; if (file_size < kTailPrefetchSize) { @@ -945,8 +954,6 @@ Status BlockBasedTable::Open(const ImmutableCFOptions& ioptions, bool need_upper_bound_check = PrefixExtractorChanged(rep->table_properties.get(), prefix_extractor); - // prefetch both index and filters, down to all partitions - const bool prefetch_all = prefetch_index_and_filter_in_cache || level == 0; BlockBasedTableOptions::IndexType index_type = new_table->UpdateIndexType(); // prefetch the first level of index const bool prefetch_index =