diff --git a/Cargo.toml b/Cargo.toml
index 5ecf949..47d0df3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,3 +30,5 @@ unwrap_used = "deny"
 cast_possible_truncation = "deny"
 cast_possible_wrap = "deny"
 cast_sign_loss = "deny"
+
+map_err_ignore = "deny"
diff --git a/src/client.rs b/src/client.rs
index 8826783..3f99639 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -41,6 +41,13 @@ pub enum ClientError {
     /// The server sent a valid frame in an invalid protocol state.
     #[error("unexpected server message: {0}")]
     UnexpectedMessage(&'static str),
+    /// An `EXPLAIN` response contained invalid UTF-8.
+    #[error("unexpected server message: EXPLAIN result is not UTF-8")]
+    InvalidExplainUtf8 {
+        /// The underlying UTF-8 decoding failure.
+        #[source]
+        source: std::str::Utf8Error,
+    },
     /// The database name is empty or exceeds the protocol limit.
     #[error("invalid database name: {0}")]
     InvalidDatabaseName(&'static str),
@@ -166,13 +173,7 @@ fn decode_complete(payload: &[u8], rows: Vec<Vec<Value>>) -> Result<QueryResult,
     };
     match kind {
         COMPLETE_ROWS => {
-            if data.len() != 8 {
-                return Err(ClientError::UnexpectedMessage("row completion count is invalid"));
-            }
-            let expected =
-                u64::from_be_bytes(data.try_into().map_err(|_| {
-                    ClientError::UnexpectedMessage("row completion count is invalid")
-                })?);
+            let expected = decode_completion_count(data, "row completion count is invalid")?;
             if expected != rows.len() as u64 {
                 return Err(ClientError::UnexpectedMessage("row completion count does not match"));
             }
@@ -181,18 +182,12 @@ fn decode_complete(payload: &[u8], rows: Vec<Vec<Value>>) -> Result<QueryResult,
         COMPLETE_EXPLAIN => {
             require_no_rows(&rows)?;
             let plan = std::str::from_utf8(data)
-                .map_err(|_| ClientError::UnexpectedMessage("EXPLAIN result is not UTF-8"))?;
+                .map_err(|source| ClientError::InvalidExplainUtf8 { source })?;
             Ok(QueryResult::Explain(plan.to_owned()))
         }
         COMPLETE_ROWS_AFFECTED => {
             require_no_rows(&rows)?;
-            if data.len() != 8 {
-                return Err(ClientError::UnexpectedMessage("rows-affected count is invalid"));
-            }
-            let count =
-                u64::from_be_bytes(data.try_into().map_err(|_| {
-                    ClientError::UnexpectedMessage("rows-affected count is invalid")
-                })?);
+            let count = decode_completion_count(data, "rows-affected count is invalid")?;
             Ok(QueryResult::RowsAffected(count))
         }
         COMPLETE_SCHEMA_AFFECTED if data.is_empty() => {
@@ -210,6 +205,13 @@ fn decode_complete(payload: &[u8], rows: Vec<Vec<Value>>) -> Result<QueryResult,
     }
 }
 
+fn decode_completion_count(data: &[u8], invalid_message: &'static str) -> Result<u64, ClientError> {
+    let [b0, b1, b2, b3, b4, b5, b6, b7] = data else {
+        return Err(ClientError::UnexpectedMessage(invalid_message));
+    };
+    Ok(u64::from_be_bytes([*b0, *b1, *b2, *b3, *b4, *b5, *b6, *b7]))
+}
+
 fn require_no_rows(rows: &[Vec<Value>]) -> Result<(), ClientError> {
     if rows.is_empty() {
         Ok(())
diff --git a/src/executor/expression.rs b/src/executor/expression.rs
index c4ea3e1..ab2dc9d 100644
--- a/src/executor/expression.rs
+++ b/src/executor/expression.rs
@@ -27,7 +27,7 @@ pub fn evaluate_expression(
 pub(super) fn execute_values(rows: Vec<Vec<PlannedExpression>>) -> ExecutorResult<ExecutionOutput> {
     let rows = rows.into_iter().enumerate().map(|(row_index, expressions)| {
         let table_key = TableKey::try_from(row_index)
-            .map_err(|_| ExecutorError::ValuesRowIndexOutOfRange { row_index })?;
+            .map_err(|_out_of_range| ExecutorError::ValuesRowIndexOutOfRange { row_index })?;
         let input = empty_record(table_key)?;
         evaluate_expressions(&expressions, &input)
     });
diff --git a/src/protocol.rs b/src/protocol.rs
index eb58ff1..11f4bc5 100644
--- a/src/protocol.rs
+++ b/src/protocol.rs
@@ -130,6 +130,24 @@ pub enum ProtocolError {
     /// A frame or message payload is malformed.
     #[error("malformed protocol message: {0}")]
     Malformed(&'static str),
+    /// A text field in a message payload is not valid UTF-8.
+    #[error("malformed protocol message: {context}")]
+    InvalidUtf8 {
+        /// Description of the malformed text field.
+        context: &'static str,
+        /// The underlying UTF-8 decoding failure.
+        #[source]
+        source: std::str::Utf8Error,
+    },
+    /// Memory for decoded row values could not be reserved.
+    #[error("failed to allocate storage for {value_count} row values")]
+    RowAllocationFailed {
+        /// Number of values declared by the row payload.
+        value_count: usize,
+        /// The underlying allocation failure.
+        #[source]
+        source: std::collections::TryReserveError,
+    },
 }
 
 #[derive(Debug, PartialEq, Eq)]
@@ -179,7 +197,7 @@ pub(crate) fn write_frame(
         return Err(ProtocolError::FrameTooLarge { length: payload.len() });
     }
     let length = u32::try_from(payload.len())
-        .map_err(|_| ProtocolError::FrameTooLarge { length: payload.len() })?;
+        .map_err(|_out_of_range| ProtocolError::FrameTooLarge { length: payload.len() })?;
     let mut header = [0_u8; HEADER_LEN];
     header[..4].copy_from_slice(&MAGIC);
     header[4..6].copy_from_slice(&VERSION.to_be_bytes());
@@ -202,14 +220,15 @@ pub(crate) fn decode_error(payload: &[u8]) -> Result<(ErrorCode, String), Protoc
         return Err(ProtocolError::Malformed("error response has no error code"));
     }
     let code = ErrorCode::from_u16(u16::from_be_bytes([payload[0], payload[1]]));
-    let message = std::str::from_utf8(&payload[2..])
-        .map_err(|_| ProtocolError::Malformed("error message is not UTF-8"))?;
+    let message = std::str::from_utf8(&payload[2..]).map_err(|source| {
+        ProtocolError::InvalidUtf8 { context: "error message is not UTF-8", source }
+    })?;
     Ok((code, message.to_owned()))
 }
 
 pub(crate) fn encode_row(values: &[Value]) -> Result<Vec<u8>, ProtocolError> {
     let count = u32::try_from(values.len())
-        .map_err(|_| ProtocolError::Malformed("row has too many values"))?;
+        .map_err(|_out_of_range| ProtocolError::Malformed("row has too many values"))?;
     let mut payload = Vec::new();
     payload.extend_from_slice(&count.to_be_bytes());
     for value in values {
@@ -218,7 +237,7 @@ pub(crate) fn encode_row(values: &[Value]) -> Result<Vec<u8>, ProtocolError> {
             Value::String(value) => {
                 payload.push(0x01);
                 let length = u32::try_from(value.len())
-                    .map_err(|_| ProtocolError::Malformed("text value is too large"))?;
+                    .map_err(|_out_of_range| ProtocolError::Malformed("text value is too large"))?;
                 payload.extend_from_slice(&length.to_be_bytes());
                 payload.extend_from_slice(value.as_bytes());
             }
@@ -258,15 +277,16 @@ pub(crate) fn decode_row(payload: &[u8]) -> Result<Vec<Value>, ProtocolError> {
     let mut values = Vec::new();
     values
         .try_reserve_exact(count)
-        .map_err(|_| ProtocolError::Malformed("cannot allocate row values"))?;
+        .map_err(|source| ProtocolError::RowAllocationFailed { value_count: count, source })?;
     for _ in 0..count {
         values.push(match decoder.u8()? {
             0x00 => Value::Null,
             0x01 => {
                 let length = decoder.u32()? as usize;
                 let bytes = decoder.bytes(length)?;
-                let value = std::str::from_utf8(bytes)
-                    .map_err(|_| ProtocolError::Malformed("text value is not UTF-8"))?;
+                let value = std::str::from_utf8(bytes).map_err(|source| {
+                    ProtocolError::InvalidUtf8 { context: "text value is not UTF-8", source }
+                })?;
                 Value::String(value.to_owned())
             }
             0x02 => match decoder.u8()? {
@@ -318,9 +338,9 @@ impl<'a> Decoder<'a> {
     }
 
     fn array<const N: usize>(&mut self) -> Result<[u8; N], ProtocolError> {
-        self.bytes(N)?
-            .try_into()
-            .map_err(|_| ProtocolError::Malformed("message payload is truncated"))
+        let mut array = [0; N];
+        array.copy_from_slice(self.bytes(N)?);
+        Ok(array)
     }
 
     fn u8(&mut self) -> Result<u8, ProtocolError> {
diff --git a/src/relational/cursor.rs b/src/relational/cursor.rs
index 9472b54..b8069a1 100644
--- a/src/relational/cursor.rs
+++ b/src/relational/cursor.rs
@@ -15,10 +15,11 @@ fn encode_table_key(table_key: TableKey) -> [u8; TABLE_KEY_SIZE] {
 }
 
 fn decode_table_key(key: &[u8]) -> StorageResult<TableKey> {
-    let bytes: [u8; TABLE_KEY_SIZE] = key.try_into().map_err(|_| PageError::CorruptCell {
-        slot_index: 0,
-        kind: CellCorruption::InvalidTableKeyLength { actual: key.len() },
-    })?;
+    let bytes: [u8; TABLE_KEY_SIZE] =
+        key.try_into().map_err(|_wrong_length| PageError::CorruptCell {
+            slot_index: 0,
+            kind: CellCorruption::InvalidTableKeyLength { actual: key.len() },
+        })?;
     Ok(TableKey::from_be_bytes(bytes) ^ TableKey::MIN)
 }
 
@@ -34,10 +35,11 @@ pub(crate) fn encode_index_entry_key(index_key: &[u8], table_key: TableKey) -> V
 }
 
 fn decode_index_table_key(value: &[u8]) -> StorageResult<TableKey> {
-    let bytes: [u8; TABLE_KEY_SIZE] = value.try_into().map_err(|_| PageError::CorruptCell {
-        slot_index: 0,
-        kind: CellCorruption::InvalidIndexTableKeyValueLength { actual: value.len() },
-    })?;
+    let bytes: [u8; TABLE_KEY_SIZE] =
+        value.try_into().map_err(|_wrong_length| PageError::CorruptCell {
+            slot_index: 0,
+            kind: CellCorruption::InvalidIndexTableKeyValueLength { actual: value.len() },
+        })?;
     Ok(TableKey::from_be_bytes(bytes) ^ TableKey::MIN)
 }
 
diff --git a/src/relational/tuple.rs b/src/relational/tuple.rs
index 2c500f8..61cdc64 100644
--- a/src/relational/tuple.rs
+++ b/src/relational/tuple.rs
@@ -434,7 +434,7 @@ where
     I::IntoIter: ExactSizeIterator,
 {
     let values = values.into_iter();
-    let value_count = u32::try_from(values.len()).map_err(|_| {
+    let value_count = u32::try_from(values.len()).map_err(|_out_of_range| {
         io::Error::new(io::ErrorKind::InvalidInput, "tuple value count exceeds u32::MAX")
     })?;
     writer.write_all(&value_count.to_le_bytes())?;
@@ -450,7 +450,7 @@ fn write_value_ref<W: Write>(writer: &mut W, value: ValueRef<'_>) -> io::Result<
     match value {
         ValueRef::Null => write_tlv_header(writer, TAG_NULL, NULL_LENGTH),
         ValueRef::String(value) => {
-            let len = u32::try_from(value.len()).map_err(|_| {
+            let len = u32::try_from(value.len()).map_err(|_out_of_range| {
                 io::Error::new(io::ErrorKind::InvalidInput, "string length exceeds u32::MAX")
             })?;
             write_tlv_header(writer, TAG_STRING, len)?;
diff --git a/src/sql_parser/parser/mod.rs b/src/sql_parser/parser/mod.rs
index 05f1086..e3e7df0 100644
--- a/src/sql_parser/parser/mod.rs
+++ b/src/sql_parser/parser/mod.rs
@@ -242,9 +242,12 @@ impl<'a> Parser<'a> {
             TokenKind::Identifier(id) => Expression::Identifier(id),
             TokenKind::Asterisk => Expression::Wildcard,
             TokenKind::LeftParen => {
-                let lhs = self
-                    .expr_bp(0)
-                    .map_err(|_| SQLError::new(SQLErrorKind::UnclosedParenthesis, token.offset))?;
+                let lhs = self.expr_bp(0).map_err(|error| match error.kind {
+                    SQLErrorKind::UnexpectedEnd => {
+                        SQLError::new(SQLErrorKind::UnclosedParenthesis, token.offset)
+                    }
+                    _ => error,
+                })?;
                 self.lexer.expect_token(TokenKind::RightParen)?;
                 lhs
             }
@@ -406,6 +409,25 @@ mod parser_tests {
         assert_eq!(Err(expected_err), parser.expr());
     }
 
+    #[test]
+    fn test_parenthesized_expression_preserves_inner_error() {
+        let parser = Parser::new("(operand invalid_operator)");
+        let expected_err = SQLError::new(
+            SQLErrorKind::InvalidOperator { op: TokenKind::Identifier("invalid_operator") },
+            9,
+        );
+
+        assert_eq!(Err(expected_err), parser.expr());
+    }
+
+    #[test]
+    fn test_unclosed_parenthesized_expression_maps_unexpected_end() {
+        let parser = Parser::new("(operand +");
+        let expected_err = SQLError::new(SQLErrorKind::UnclosedParenthesis, 0);
+
+        assert_eq!(Err(expected_err), parser.expr());
+    }
+
     #[test]
     fn test_parse_inequality_operators() {
         let s = "12 < 34";
diff --git a/src/storage/btree/rebalance.rs b/src/storage/btree/rebalance.rs
index 9d1760f..8118eb3 100644
--- a/src/storage/btree/rebalance.rs
+++ b/src/storage/btree/rebalance.rs
@@ -147,8 +147,9 @@ impl TreeCursor {
         if child_index == usize::from(slot_count) {
             return Ok(interior.rightmost_child());
         }
-        let slot_index = u16::try_from(child_index)
-            .map_err(|_| PageError::InvalidSlotIndex { slot_index: u16::MAX, slot_count })?;
+        let slot_index = u16::try_from(child_index).map_err(|_out_of_range| {
+            PageError::InvalidSlotIndex { slot_index: u16::MAX, slot_count }
+        })?;
         if slot_index > slot_count {
             return Err(PageError::InvalidSlotIndex { slot_index, slot_count }.into());
         }
diff --git a/src/storage/btree/rebalance_repair.rs b/src/storage/btree/rebalance_repair.rs
index 5a370af..882fbd6 100644
--- a/src/storage/btree/rebalance_repair.rs
+++ b/src/storage/btree/rebalance_repair.rs
@@ -123,7 +123,7 @@ impl TreeCursor {
                 let child_ref = if child_index + 1 == child_count {
                     ChildSlotRef::Rightmost
                 } else {
-                    let slot_index = u16::try_from(child_index).map_err(|_| {
+                    let slot_index = u16::try_from(child_index).map_err(|_out_of_range| {
                         PageError::InvalidSlotIndex { slot_index: u16::MAX, slot_count }
                     })?;
                     ChildSlotRef::Slot(slot_index)
diff --git a/src/storage/btree/split.rs b/src/storage/btree/split.rs
index f05b7d5..034326a 100644
--- a/src/storage/btree/split.rs
+++ b/src/storage/btree/split.rs
@@ -317,7 +317,7 @@ impl TreeCursor {
             .ok_or(StorageError::Internal(InternalError::InvariantViolation(
                 InvariantViolation::LeafSplitTargetMissing,
             )))?;
-        let target_slot_index = u16::try_from(target_slot_index).map_err(|_| {
+        let target_slot_index = u16::try_from(target_slot_index).map_err(|_out_of_range| {
             StorageError::Internal(InternalError::InvariantViolation(
                 InvariantViolation::LeafSplitTargetSlotOutOfRange { slot_index: target_slot_index },
             ))
diff --git a/src/storage/log_manager/frame.rs b/src/storage/log_manager/frame.rs
index 221a390..b1c8612 100644
--- a/src/storage/log_manager/frame.rs
+++ b/src/storage/log_manager/frame.rs
@@ -36,7 +36,7 @@ pub(super) fn serialize_transaction<'a, W: Write>(
 ) -> Result<(), LogManagerError> {
     validate_record_txn_ids(txn_id, records)?;
     let entry_count = u32::try_from(records.len())
-        .map_err(|_| LogManagerError::TooManyRecords { count: records.len() })?;
+        .map_err(|_out_of_range| LogManagerError::TooManyRecords { count: records.len() })?;
     let payload_len = serialized_records_len(records)?;
 
     write_frame_header(&mut writer, txn_id, entry_count, payload_len)?;
@@ -87,7 +87,7 @@ pub(super) fn deserialize_transaction(
     let entry_count = cursor.read_u32()?;
     let payload_len = cursor.read_u64()?;
     let payload_len = usize::try_from(payload_len)
-        .map_err(|_| LogManagerError::PayloadLengthTooLarge { payload_len })?;
+        .map_err(|_out_of_range| LogManagerError::PayloadLengthTooLarge { payload_len })?;
 
     let payload_start = cursor.position;
     let payload_end =
@@ -163,8 +163,9 @@ pub(super) fn scan_transaction_frame<R: Read>(
         return Ok(None);
     };
     let header = parse_header(&header_bytes)?;
-    let payload_len = usize::try_from(header.payload_len)
-        .map_err(|_| LogManagerError::PayloadLengthTooLarge { payload_len: header.payload_len })?;
+    let payload_len = usize::try_from(header.payload_len).map_err(|_out_of_range| {
+        LogManagerError::PayloadLengthTooLarge { payload_len: header.payload_len }
+    })?;
     let mut remaining = payload_len;
     let mut digest = CRC32.digest();
     let mut actual_record_count = 0usize;
@@ -361,12 +362,12 @@ pub(super) fn transaction_frame_len(buf: &'_ [u8]) -> Result<usize, LogManagerEr
         return Err(LogManagerError::TruncatedFrame { needed: HEADER_LEN, remaining: buf.len() });
     }
 
-    let header_bytes: &[u8; HEADER_LEN] = (&buf[..HEADER_LEN]).try_into().map_err(|_| {
-        LogManagerError::TruncatedFrame { needed: HEADER_LEN, remaining: buf.len() }
+    let mut header_bytes = [0; HEADER_LEN];
+    header_bytes.copy_from_slice(&buf[..HEADER_LEN]);
+    let header = parse_header(&header_bytes)?;
+    let payload_len = usize::try_from(header.payload_len).map_err(|_out_of_range| {
+        LogManagerError::PayloadLengthTooLarge { payload_len: header.payload_len }
     })?;
-    let header = parse_header(header_bytes)?;
-    let payload_len = usize::try_from(header.payload_len)
-        .map_err(|_| LogManagerError::PayloadLengthTooLarge { payload_len: header.payload_len })?;
 
     HEADER_LEN
         .checked_add(payload_len)
@@ -464,10 +465,10 @@ fn serialized_record_len<'a>(kind: &LogRecordKind<'a>) -> Result<u64, LogManager
         LogRecordKind::PageUpdate { redo_data, undo_data, .. } => {
             validate_page_image_len(redo_data)?;
             validate_page_image_len(undo_data)?;
-            let redo_len = u32::try_from(redo_data.len()).map_err(|_| {
+            let redo_len = u32::try_from(redo_data.len()).map_err(|_out_of_range| {
                 LogManagerError::PayloadLengthTooLarge { payload_len: redo_data.len() as u64 }
             })?;
-            let undo_len = u32::try_from(undo_data.len()).map_err(|_| {
+            let undo_len = u32::try_from(undo_data.len()).map_err(|_out_of_range| {
                 LogManagerError::PayloadLengthTooLarge { payload_len: undo_data.len() as u64 }
             })?;
             Ok(1 + 8 + 4 + 4 + u64::from(redo_len) + u64::from(undo_len))
@@ -523,10 +524,10 @@ fn write_log_record_payload<'a, W: Write>(
         LogRecordKind::PageUpdate { page_id, redo_data, undo_data } => {
             validate_page_image_len(redo_data)?;
             validate_page_image_len(undo_data)?;
-            let redo_len = u32::try_from(redo_data.len()).map_err(|_| {
+            let redo_len = u32::try_from(redo_data.len()).map_err(|_out_of_range| {
                 LogManagerError::PayloadLengthTooLarge { payload_len: redo_data.len() as u64 }
             })?;
-            let undo_len = u32::try_from(undo_data.len()).map_err(|_| {
+            let undo_len = u32::try_from(undo_data.len()).map_err(|_out_of_range| {
                 LogManagerError::PayloadLengthTooLarge { payload_len: undo_data.len() as u64 }
             })?;
 
diff --git a/src/storage/log_manager/mod.rs b/src/storage/log_manager/mod.rs
index 21867af..ebf7145 100644
--- a/src/storage/log_manager/mod.rs
+++ b/src/storage/log_manager/mod.rs
@@ -441,7 +441,7 @@ impl LogManager {
         validate_record_txn_ids(txn_id, records)?;
 
         let record_count = u64::try_from(records.len())
-            .map_err(|_| LogManagerError::TooManyRecords { count: records.len() })?;
+            .map_err(|_out_of_range| LogManagerError::TooManyRecords { count: records.len() })?;
         let lsn = self
             .highest_appended_lsn
             .unwrap_or(ZERO_LSN)
@@ -687,9 +687,8 @@ impl RecoveryLogRecordKind {
 }
 
 fn page_image_array(image: &[u8]) -> Result<Box<[u8; PAGE_SIZE]>, LogManagerError> {
-    let image = image.try_into().map_err(|_| LogManagerError::InvalidPageImageLength {
-        expected: PAGE_SIZE,
-        actual: image.len(),
+    let image = image.try_into().map_err(|_wrong_length| {
+        LogManagerError::InvalidPageImageLength { expected: PAGE_SIZE, actual: image.len() }
     })?;
     Ok(Box::new(image))
 }
diff --git a/src/storage/page/core.rs b/src/storage/page/core.rs
index a0b2a88..618e180 100644
--- a/src/storage/page/core.rs
+++ b/src/storage/page/core.rs
@@ -120,7 +120,8 @@ impl Freeblock {
 }
 
 fn encode_page_u16(value: usize) -> PageResult<u16> {
-    u16::try_from(value).map_err(|_| PageError::CellTooLarge { len: value, max: u16::MAX as usize })
+    u16::try_from(value)
+        .map_err(|_out_of_range| PageError::CellTooLarge { len: value, max: u16::MAX as usize })
 }
 
 #[derive(Debug, Clone, Copy)]
diff --git a/src/storage/page/interior.rs b/src/storage/page/interior.rs
index 8072fa0..0a47e43 100644
--- a/src/storage/page/interior.rs
+++ b/src/storage/page/interior.rs
@@ -177,8 +177,9 @@ where
         first_overflow_page_id: Option<PageId>,
         inline_payload: &[u8],
     ) -> PageResult<SlotId> {
-        let encoded_key_len = u16::try_from(key_len)
-            .map_err(|_| PageError::CellTooLarge { len: key_len, max: u16::MAX as usize })?;
+        let encoded_key_len = u16::try_from(key_len).map_err(|_out_of_range| {
+            PageError::CellTooLarge { len: key_len, max: u16::MAX as usize }
+        })?;
         let Some(expected_inline_len) = format::inline_payload_len(key_len, first_overflow_page_id)
         else {
             return Err(PageError::CellTooLarge { len: key_len, max: u16::MAX as usize });
diff --git a/src/storage/page/leaf.rs b/src/storage/page/leaf.rs
index 6884503..8f61fee 100644
--- a/src/storage/page/leaf.rs
+++ b/src/storage/page/leaf.rs
@@ -119,12 +119,15 @@ fn validate_payload_parts(
     let payload_len = key_len
         .checked_add(value_len)
         .ok_or(PageError::CellTooLarge { len: usize::MAX, max: u16::MAX as usize })?;
-    let encoded_key_len = u16::try_from(key_len)
-        .map_err(|_| PageError::CellTooLarge { len: payload_len, max: u16::MAX as usize })?;
-    let encoded_value_len = u16::try_from(value_len)
-        .map_err(|_| PageError::CellTooLarge { len: payload_len, max: u16::MAX as usize })?;
-    let encoded_payload_len = u16::try_from(payload_len)
-        .map_err(|_| PageError::CellTooLarge { len: payload_len, max: u16::MAX as usize })?;
+    let encoded_key_len = u16::try_from(key_len).map_err(|_out_of_range| {
+        PageError::CellTooLarge { len: payload_len, max: u16::MAX as usize }
+    })?;
+    let encoded_value_len = u16::try_from(value_len).map_err(|_out_of_range| {
+        PageError::CellTooLarge { len: payload_len, max: u16::MAX as usize }
+    })?;
+    let encoded_payload_len = u16::try_from(payload_len).map_err(|_out_of_range| {
+        PageError::CellTooLarge { len: payload_len, max: u16::MAX as usize }
+    })?;
     let Some(expected_inline_len) = format::inline_payload_len(payload_len, first_overflow_page_id)
     else {
         return Err(PageError::CellTooLarge { len: payload_len, max: u16::MAX as usize });
diff --git a/src/storage/page_cache.rs b/src/storage/page_cache.rs
index 49a8883..fa05c58 100644
--- a/src/storage/page_cache.rs
+++ b/src/storage/page_cache.rs
@@ -271,7 +271,7 @@ impl PageCache {
         self.inner.runtime.read_page(new_page_id, &mut data)?;
 
         {
-            let mut frame_data = frame.data.try_borrow_mut().map_err(|_| {
+            let mut frame_data = frame.data.try_borrow_mut().map_err(|_borrow_conflict| {
                 PageCacheError::PageMutableBorrowConflict {
                     page_id: old_page_id.unwrap_or(new_page_id),
                 }
@@ -307,7 +307,7 @@ impl PageCache {
         let page = frame
             .data
             .try_borrow()
-            .map_err(|_| PageCacheError::PageImmutableBorrowConflict { page_id })?;
+            .map_err(|_borrow_conflict| PageCacheError::PageImmutableBorrowConflict { page_id })?;
         self.inner
             .runtime
             .flush_wal_through(frame.lsn.get())
@@ -325,7 +325,7 @@ impl PageCache {
             let pin = self.fetch_page(restore.page_id)?;
             let frame = &self.inner.frames[pin.frame_id];
             {
-                let mut data = frame.data.try_borrow_mut().map_err(|_| {
+                let mut data = frame.data.try_borrow_mut().map_err(|_borrow_conflict| {
                     PageCacheError::PageMutableBorrowConflict { page_id: restore.page_id }
                 })?;
                 *data = restore.image;
@@ -369,10 +369,9 @@ impl PinGuard {
     /// fails while a write guard is active.
     pub(crate) fn read(&self) -> PageCacheResult<PageReadGuard<'_>> {
         let frame = &self.page_cache.frames[self.frame_id];
-        let page = frame
-            .data
-            .try_borrow()
-            .map_err(|_| PageCacheError::PageImmutableBorrowConflict { page_id: self.page_id })?;
+        let page = frame.data.try_borrow().map_err(|_borrow_conflict| {
+            PageCacheError::PageImmutableBorrowConflict { page_id: self.page_id }
+        })?;
         Ok(PageReadGuard { page })
     }
 
@@ -383,10 +382,9 @@ impl PinGuard {
     /// caller later decides not to mutate the page bytes.
     pub(crate) fn write(&self) -> PageCacheResult<PageWriteGuard<'_>> {
         let frame = &self.page_cache.frames[self.frame_id];
-        let page = frame
-            .data
-            .try_borrow_mut()
-            .map_err(|_| PageCacheError::PageMutableBorrowConflict { page_id: self.page_id })?;
+        let page = frame.data.try_borrow_mut().map_err(|_borrow_conflict| {
+            PageCacheError::PageMutableBorrowConflict { page_id: self.page_id }
+        })?;
         let before = *page;
         let was_dirty = frame.dirty.get();
         frame.dirty.set(true);