diff --git a/snuba/clickhouse/translators/snuba/mappers.py b/snuba/clickhouse/translators/snuba/mappers.py
index 07f6384870e..452d140ef09 100644
--- a/snuba/clickhouse/translators/snuba/mappers.py
+++ b/snuba/clickhouse/translators/snuba/mappers.py
@@ -1,6 +1,6 @@
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
-from typing import Mapping, Optional, Tuple
+from typing import Optional, Tuple
 
 from snuba.clickhouse.translators.snuba import SnubaClickhouseStrictTranslator
 from snuba.clickhouse.translators.snuba.allowed import (
@@ -9,7 +9,7 @@
     SubscriptableReferenceMapper,
     ValidColumnMappings,
 )
-from snuba.query.dsl import arrayElement, column, literal
+from snuba.query.dsl import arrayElement
 from snuba.query.expressions import Column as ColumnExpr
 from snuba.query.expressions import CurriedFunctionCall, Expression
 from snuba.query.expressions import FunctionCall as FunctionCallExpr
@@ -239,12 +239,6 @@ class SubscriptableHashBucketMapper(SubscriptableReferenceMapper):
     from_column_name: str
     to_col_table: Optional[str]
     to_col_name: str
-    # the result is cast to this type
-    data_type: str
-    # if you add {'sentry.span_id': 'span_id'} here, then if the user requests attr_blah[sentry.span_id],
-    # this mapper will return a reference to the actual column instead of attr_str.
-    # if specified, data_type must also be specified.
-    normalized_columns: Optional[Mapping[str, str]] = None
 
     def attempt_map(
         self,
@@ -263,24 +257,12 @@ def attempt_map(
             return None
 
         bucket_idx = fnv_1a(key.value.encode("utf-8")) % ATTRIBUTE_BUCKETS
-        expr: Expression = arrayElement(
-            None,
+        return arrayElement(
+            expression.alias,
             ColumnExpr(None, self.to_col_table, f"{self.to_col_name}_{bucket_idx}"),
             key,
         )
 
-        if self.normalized_columns and key.value in self.normalized_columns:
-            expr = column(self.normalized_columns[key.value])
-
-        return FunctionCallExpr(
-            expression.alias,
-            "CAST",
-            (
-                expr,
-                literal(self.data_type),
-            ),
-        )
-
 
 @dataclass(frozen=True)
 class ColumnToMapping(ColumnToExpression):
diff --git a/snuba/query/processors/logical/eap_map_access_remapper.py b/snuba/query/processors/logical/eap_map_access_remapper.py
new file mode 100644
index 00000000000..0eb315945e7
--- /dev/null
+++ b/snuba/query/processors/logical/eap_map_access_remapper.py
@@ -0,0 +1,102 @@
+from typing import Sequence
+
+from snuba.query.expressions import Column, Expression, FunctionCall, Literal
+from snuba.query.logical import Query
+from snuba.query.processors.logical import LogicalQueryProcessor
+from snuba.query.query_settings import QuerySettings
+from snuba.utils.constants import ATTRIBUTE_BUCKETS
+from snuba.utils.hashes import fnv_1a
+
+
+class HashBucketFunctionTransformer(LogicalQueryProcessor):
+    """
+    In eap_spans, we split up map columns for better performance.
+    In the entity, attr_str Map(String, String) becomes
+    attr_str_0 Map(String, String),
+    attr_str_1 Map(String, String),
+    etc.
+
+    This transformer converts mapKeys(attr_str) to arrayConcat(mapKeys(attr_str_0), mapKeys(attr_str_1), ...)
+    and the same for mapValues
+
+    It converts mapExists(attr_str, 'blah') to mapExists(attr_str_{hash('blah')%20}, 'blah')
+    """
+
+    def __init__(self, hash_bucket_names: Sequence[str]):
+        super().__init__()
+        self.hash_bucket_names = set(hash_bucket_names)
+
+    def process_query(self, query: Query, query_settings: QuerySettings) -> None:
+        def transform_map_keys_and_values_expression(exp: Expression) -> Expression:
+            if not isinstance(exp, FunctionCall):
+                return exp
+
+            if len(exp.parameters) != 1:
+                return exp
+
+            param = exp.parameters[0]
+            if not isinstance(param, Column):
+                return exp
+
+            if param.column_name not in self.hash_bucket_names:
+                return exp
+
+            if exp.function_name not in ("mapKeys", "mapValues"):
+                return exp
+
+            return FunctionCall(
+                alias=exp.alias,
+                function_name="arrayConcat",
+                parameters=tuple(
+                    FunctionCall(
+                        None,
+                        function_name=exp.function_name,
+                        parameters=(
+                            Column(
+                                None,
+                                column_name=f"{param.column_name}_{i}",
+                                table_name=param.table_name,
+                            ),
+                        ),
+                    )
+                    for i in range(ATTRIBUTE_BUCKETS)
+                ),
+            )
+
+        def transform_map_contains_expression(exp: Expression) -> Expression:
+            if not isinstance(exp, FunctionCall):
+                return exp
+
+            if len(exp.parameters) != 2:
+                return exp
+
+            column = exp.parameters[0]
+            if not isinstance(column, Column):
+                return exp
+
+            if column.column_name not in self.hash_bucket_names:
+                return exp
+
+            if exp.function_name != "mapContains":
+                return exp
+
+            key = exp.parameters[1]
+            if not isinstance(key, Literal) or not isinstance(key.value, str):
+                return exp
+
+            bucket_idx = fnv_1a(key.value.encode("utf-8")) % ATTRIBUTE_BUCKETS
+            return FunctionCall(
+                alias=exp.alias,
+                function_name=exp.function_name,
+                parameters=(
+                    Column(
+                        None,
+                        None,
+                        f"{column.column_name}_{bucket_idx}",
+                    ),
+                    key,
+                ),
+            )
+
+        query.transform_expressions(transform_map_keys_and_values_expression)
+        query.transform_expressions(transform_map_contains_expression)