diff --git a/app/lib/dal/indexDAL/sqlite/SqliteTransactions.ts b/app/lib/dal/indexDAL/sqlite/SqliteTransactions.ts
index 948249c1e376e3e9411061f720a2fa8e5774e81c..af3360ecd853df127afdea381d71a4cfe35aab5a 100644
--- a/app/lib/dal/indexDAL/sqlite/SqliteTransactions.ts
+++ b/app/lib/dal/indexDAL/sqlite/SqliteTransactions.ts
@@ -18,14 +18,14 @@ export class SqliteTransactions extends SqliteTable<DBTx> implements TxsDAO {
       "txs",
       {
         hash: new SqlNotNullableFieldDefinition("VARCHAR", true, 70),
-        block_number: new SqlNullableFieldDefinition("INT", true),
+        block_number: new SqlNullableFieldDefinition("INT", true /*need by getTxHistoryByPubkeyBetweenBlocks() */),
         locktime: new SqlNullableFieldDefinition("INT", false),
         version: new SqlNullableFieldDefinition("INT", false),
         currency: new SqlNullableFieldDefinition("VARCHAR", false, 10),
         comment: new SqlNullableFieldDefinition("TEXT", false),
-        blockstamp: new SqlNullableFieldDefinition("VARCHAR", false, 100),
-        blockstampTime: new SqlNullableFieldDefinition("INT", false),
-        time: new SqlNullableFieldDefinition("INT", false),
+        blockstamp: new SqlNullableFieldDefinition("VARCHAR", true /* need by getWrittenOn() */, 100),
+        blockstampTime: new SqlNullableFieldDefinition("INT", true /* need by trimExpiredNonWrittenTxs() */),
+        time: new SqlNullableFieldDefinition("INT", true /*need by getTxHistoryByPubkeyBetweenTimes() */ ),
         inputs: new SqlNullableFieldDefinition("JSON", false),
         unlocks: new SqlNullableFieldDefinition("JSON", false),
         outputs: new SqlNullableFieldDefinition("JSON", false),
@@ -42,8 +42,8 @@ export class SqliteTransactions extends SqliteTable<DBTx> implements TxsDAO {
           50
         ) /* computed column - need by getTxHistoryXxx() */,
         recipients: new SqlNullableFieldDefinition("JSON", false),
-        written: new SqlNotNullableFieldDefinition("BOOLEAN", true),
-        removed: new SqlNotNullableFieldDefinition("BOOLEAN", true),
+        written: new SqlNotNullableFieldDefinition("BOOLEAN", true /* need by getTxHistoryMempool() */),
+        removed: new SqlNotNullableFieldDefinition("BOOLEAN", true /* need by getSandboxTs() */),
         received: new SqlNullableFieldDefinition("BOOLEAN", false),
         output_base: new SqlNullableFieldDefinition("INT", false),
         output_amount: new SqlNullableFieldDefinition("INT", false),