```sql
CREATE TABLE t
(
   id Int64, 
   d String,
   p Map(String, String)
   
)
ENGINE = ReplacingMergeTree order by id settings index_granularity  = 0;


insert into t values (1,  's', {'a':'b'});

CH starts eating RAM until it crashes

the same with

insert into t select 1,  's', map('a','b');

```

{
    if (number_of_free_entries_in_pool_to_execute_mutation > background_pool_tasks)
    {
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "The value of 'number_of_free_entries_in_pool_to_execute_mutation' setting"
            " ({}) (default values are defined in <merge_tree> section of config.xml"
            " or the value can be specified per table in SETTINGS section of CREATE TABLE query)"
            " is greater than the value of 'background_pool_size'*'background_merges_mutations_concurrency_ratio'"
            " ({}) (the value is defined in users.xml for default profile)."
            " This indicates incorrect configuration because mutations cannot work with these settings.",
            number_of_free_entries_in_pool_to_execute_mutation,
            background_pool_tasks);
    }
    if (number_of_free_entries_in_pool_to_lower_max_size_of_merge > background_pool_tasks)
    {
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "The value of 'number_of_free_entries_in_pool_to_lower_max_size_of_merge' setting"
            " ({}) (default values are defined in <merge_tree> section of config.xml"
            " or the value can be specified per table in SETTINGS section of CREATE TABLE query)"
            " is greater than the value of 'background_pool_size'*'background_merges_mutations_concurrency_ratio'"
            " ({}) (the value is defined in users.xml for default profile)."
            " This indicates incorrect configuration because the maximum size of merge will be always lowered.",