diff --git a/src/mito2/src/config.rs b/src/mito2/src/config.rs
index 5e95c2e221..602f5508ba 100644
--- a/src/mito2/src/config.rs
+++ b/src/mito2/src/config.rs
@@ -321,10 +321,10 @@ impl MitoConfig {
         );
         // Use 2x of global write buffer size as global write buffer reject size.
         let global_write_buffer_reject_size = global_write_buffer_size * 2;
-        // shouldn't be greater than 256MB in default mode.
+        // shouldn't be greater than 128MB in default mode.
         let sst_meta_cache_size = cmp::min(
             sys_memory / SST_META_CACHE_SIZE_FACTOR,
-            ReadableSize::mb(256),
+            ReadableSize::mb(128),
         );
         // shouldn't be greater than 512MB in default mode.
         let mem_cache_size = cmp::min(sys_memory / MEM_CACHE_SIZE_FACTOR, ReadableSize::mb(512));
diff --git a/src/mito2/src/sst/parquet.rs b/src/mito2/src/sst/parquet.rs
index 11eaf4d4a8..989aeb812b 100644
--- a/src/mito2/src/sst/parquet.rs
+++ b/src/mito2/src/sst/parquet.rs
@@ -39,9 +39,9 @@ pub mod writer;
 pub const PARQUET_METADATA_KEY: &str = "greptime:metadata";
 
 /// Default batch size to read parquet files.
-pub(crate) const DEFAULT_READ_BATCH_SIZE: usize = 4096;
+pub(crate) const DEFAULT_READ_BATCH_SIZE: usize = 1024;
 /// Default row group size for parquet files.
-pub const DEFAULT_ROW_GROUP_SIZE: usize = 100 * 1024;
+pub const DEFAULT_ROW_GROUP_SIZE: usize = 100 * DEFAULT_READ_BATCH_SIZE;
 
 /// Parquet write options.
 #[derive(Debug, Clone)]