Hi,
I've just experienced the same problem posted on http://www.devart.com/forums/viewtopic.php?p=78102. IDE or not, I still get a "Lost connection to MySQL server during query". Full Exception stack is below.
My setup was as follows:
I had a connection open, and I was iterating over ~6000 records (as an IQueryable), taking data from each record and constructing a new OR object (the new OR objects are detached from the context). Each new OR object went into an IList which later would be BulkLoaded, but I never get that far. About 70-80 records into my foreach loop, I encounter the problem below.
My timeout parameters at the server are long. Nothing is shorter than 5 minutes; this occurs a few seconds into my process.
I see that dotConnect for MySql 6.70 is out, but I don't want to upgrade (yet - I am running 6.50.250) unless there is some known issue in there that would address this.
Any help would greatly be appreciated.
Thanks!
Error on reading data from IDataReader.
at Devart.Data.Linq.LinqCommandExecutionException.CanThrowLinqCommandExecutionException(String message, Exception e)
at Devart.Data.Linq.Provider.ObjectReader`1.MoveNext()
at System.Linq.Seq.d__20`1.MoveNext() in C:\dev\wrkspc.......:line 486
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
at Extract.KPIs() in C:\dev\wrkspc.................:line 162
Lost connection to MySQL server during query
at Devart.Common.aj.a(Exception A_0)
at Devart.Data.MySql.bh.a(Exception A_0)
at Devart.Common.s.e(Byte[] A_0, Int32 A_1, Int32 A_2)
at Devart.Data.MySql.bk.a(Byte[] A_0, Int32 A_1, Int32 A_2)
at Devart.Data.MySql.bk.a()
at Devart.Data.MySql.bk.b(Byte[] A_0)
at Devart.Data.MySql.u.a(Byte[] A_0)
at Devart.Data.MySql.u.a(Byte[] A_0, Boolean A_1)
at Devart.Data.MySql.an.f()
at Devart.Data.MySql.a2.b(Boolean A_0)
at Devart.Data.MySql.MySqlDataReader.a(Boolean A_0)
at Devart.Data.MySql.MySqlDataReader.System.IDisposable.Dispose()
at Devart.Common.l.a(Int32 A_0, Object A_1, Int32 A_2, Object A_3)
at Devart.Common.l.a.a(Int32 A_0, Int32 A_1, Object A_2, l A_3)
at Devart.Common.l.a(Int32 A_0, Int32 A_1, Object A_2)
at Devart.Common.DbConnectionInternal.a(Int32 A_0, Int32 A_1)
at Devart.Common.DbConnectionBase.Close()
at Devart.Data.MySql.MySqlConnection.Close()
Lost connection to MySql server during query
-
StanislavK
- Devart Team
- Posts: 1710
- Joined: Thu 03 Dec 2009 10:48
Could you please specify the following:
- the data types available in the table you are querying (if possible, please specify the script needed to create this table);
- an approximate size of a row in this table;
- the version of the MySQL server you are working with;
- the list of server variables.
For example, this issue may occur if the table contains large BLOB or text data, and the max_allowed_packet server variable is small.
- the data types available in the table you are querying (if possible, please specify the script needed to create this table);
- an approximate size of a row in this table;
- the version of the MySQL server you are working with;
- the list of server variables.
For example, this issue may occur if the table contains large BLOB or text data, and the max_allowed_packet server variable is small.
Data Types in table are: INT(11), DateTime, VarChar, and Text. The specific result set I am trying to iterate over actually returns ~4k rows, each containing a TEXT object that is ~4k ~4.5k characters in length.
I am running MySQL 5.0.51a-3ubuntu5.8.
Variables is use are below, and the max_allowed_packet size is 16776192. That's about 15MB. Is that limit per row, or per set? My result set is 4300 rows, ~275MB. Currently, I do the following:
IQueryable match = _context.Metrics.Where(c => (c.Name.Equals(kpi.MetricName)));
And I loop over the IQueryable result set in a foreach loop.
That IQueryable result set is the large problematic one. Is there a recommended way to page/loop through a set like that?
Thanks!
I am running MySQL 5.0.51a-3ubuntu5.8.
Variables is use are below, and the max_allowed_packet size is 16776192. That's about 15MB. Is that limit per row, or per set? My result set is 4300 rows, ~275MB. Currently, I do the following:
IQueryable match = _context.Metrics.Where(c => (c.Name.Equals(kpi.MetricName)));
And I loop over the IQueryable result set in a foreach loop.
That IQueryable result set is the large problematic one. Is there a recommended way to page/loop through a set like that?
Thanks!
Code: Select all
=======================================================================================================
| Variable_name | Value |
=======================================================================================================
| auto_increment_increment | 1 |
-------------------------------------------------------------------------------------------------------
| auto_increment_offset | 1 |
-------------------------------------------------------------------------------------------------------
| automatic_sp_privileges | ON |
-------------------------------------------------------------------------------------------------------
| back_log | 50 |
-------------------------------------------------------------------------------------------------------
| basedir | /usr/ |
-------------------------------------------------------------------------------------------------------
| binlog_cache_size | 32768 |
-------------------------------------------------------------------------------------------------------
| bulk_insert_buffer_size | 8388608 |
-------------------------------------------------------------------------------------------------------
| character_set_client | utf8 |
-------------------------------------------------------------------------------------------------------
| character_set_connection | utf8 |
-------------------------------------------------------------------------------------------------------
| character_set_database | utf8 |
-------------------------------------------------------------------------------------------------------
| character_set_filesystem | binary |
-------------------------------------------------------------------------------------------------------
| character_set_results | utf8 |
-------------------------------------------------------------------------------------------------------
| character_set_server | latin1 |
-------------------------------------------------------------------------------------------------------
| character_set_system | utf8 |
-------------------------------------------------------------------------------------------------------
| character_sets_dir | /usr/share/mysql/charsets/ |
-------------------------------------------------------------------------------------------------------
| collation_connection | utf8_general_ci |
-------------------------------------------------------------------------------------------------------
| collation_database | utf8_general_ci |
-------------------------------------------------------------------------------------------------------
| collation_server | latin1_swedish_ci |
-------------------------------------------------------------------------------------------------------
| completion_type | 0 |
-------------------------------------------------------------------------------------------------------
| concurrent_insert | 1 |
-------------------------------------------------------------------------------------------------------
| connect_timeout | 300 |
-------------------------------------------------------------------------------------------------------
| datadir | /var/lib/mysql/ |
-------------------------------------------------------------------------------------------------------
| date_format | %Y-%m-%d |
-------------------------------------------------------------------------------------------------------
| datetime_format | %Y-%m-%d %H:%i:%s |
-------------------------------------------------------------------------------------------------------
| default_week_format | 0 |
-------------------------------------------------------------------------------------------------------
| delay_key_write | ON |
-------------------------------------------------------------------------------------------------------
| delayed_insert_limit | 100 |
-------------------------------------------------------------------------------------------------------
| delayed_insert_timeout | 300 |
-------------------------------------------------------------------------------------------------------
| delayed_queue_size | 1000 |
-------------------------------------------------------------------------------------------------------
| div_precision_increment | 4 |
-------------------------------------------------------------------------------------------------------
| keep_files_on_create | OFF |
-------------------------------------------------------------------------------------------------------
| engine_condition_pushdown | OFF |
-------------------------------------------------------------------------------------------------------
| expire_logs_days | 10 |
-------------------------------------------------------------------------------------------------------
| flush | OFF |
-------------------------------------------------------------------------------------------------------
| flush_time | 0 |
-------------------------------------------------------------------------------------------------------
| ft_boolean_syntax | + -><()~*:""&| |
-------------------------------------------------------------------------------------------------------
| ft_max_word_len | 84 |
-------------------------------------------------------------------------------------------------------
| ft_min_word_len | 4 |
-------------------------------------------------------------------------------------------------------
| ft_query_expansion_limit | 20 |
-------------------------------------------------------------------------------------------------------
| ft_stopword_file | (built-in) |
-------------------------------------------------------------------------------------------------------
| group_concat_max_len | 1024 |
-------------------------------------------------------------------------------------------------------
| have_archive | YES |
-------------------------------------------------------------------------------------------------------
| have_bdb | NO |
-------------------------------------------------------------------------------------------------------
| have_blackhole_engine | YES |
-------------------------------------------------------------------------------------------------------
| have_compress | YES |
-------------------------------------------------------------------------------------------------------
| have_crypt | YES |
-------------------------------------------------------------------------------------------------------
| have_csv | YES |
-------------------------------------------------------------------------------------------------------
| have_dynamic_loading | YES |
-------------------------------------------------------------------------------------------------------
| have_example_engine | NO |
-------------------------------------------------------------------------------------------------------
| have_federated_engine | YES |
-------------------------------------------------------------------------------------------------------
| have_geometry | YES |
-------------------------------------------------------------------------------------------------------
| have_innodb | YES |
-------------------------------------------------------------------------------------------------------
| have_isam | NO |
-------------------------------------------------------------------------------------------------------
| have_merge_engine | YES |
-------------------------------------------------------------------------------------------------------
| have_ndbcluster | DISABLED |
-------------------------------------------------------------------------------------------------------
| have_openssl | DISABLED |
-------------------------------------------------------------------------------------------------------
| have_ssl | DISABLED |
-------------------------------------------------------------------------------------------------------
| have_query_cache | YES |
-------------------------------------------------------------------------------------------------------
| have_raid | NO |
-------------------------------------------------------------------------------------------------------
| have_rtree_keys | YES |
-------------------------------------------------------------------------------------------------------
| have_symlink | YES |
-------------------------------------------------------------------------------------------------------
| hostname | coverity-lnx01 |
-------------------------------------------------------------------------------------------------------
| init_connect | |
-------------------------------------------------------------------------------------------------------
| init_file | |
-------------------------------------------------------------------------------------------------------
| init_slave | |
-------------------------------------------------------------------------------------------------------
| innodb_additional_mem_pool_size | 1048576 |
-------------------------------------------------------------------------------------------------------
| innodb_autoextend_increment | 8 |
-------------------------------------------------------------------------------------------------------
| innodb_buffer_pool_awe_mem_mb | 0 |
-------------------------------------------------------------------------------------------------------
| innodb_buffer_pool_size | 8388608 |
-------------------------------------------------------------------------------------------------------
| innodb_checksums | ON |
-------------------------------------------------------------------------------------------------------
| innodb_commit_concurrency | 0 |
-------------------------------------------------------------------------------------------------------
| innodb_concurrency_tickets | 500 |
-------------------------------------------------------------------------------------------------------
| innodb_data_file_path | ibdata1:10M:autoextend |
-------------------------------------------------------------------------------------------------------
| innodb_data_home_dir | |
-------------------------------------------------------------------------------------------------------
| innodb_doublewrite | ON |
-------------------------------------------------------------------------------------------------------
| innodb_fast_shutdown | 1 |
-------------------------------------------------------------------------------------------------------
| innodb_file_io_threads | 4 |
-------------------------------------------------------------------------------------------------------
| innodb_file_per_table | OFF |
-------------------------------------------------------------------------------------------------------
| innodb_flush_log_at_trx_commit | 1 |
-------------------------------------------------------------------------------------------------------
| innodb_flush_method | |
-------------------------------------------------------------------------------------------------------
| innodb_force_recovery | 0 |
-------------------------------------------------------------------------------------------------------
| innodb_lock_wait_timeout | 50 |
-------------------------------------------------------------------------------------------------------
| innodb_locks_unsafe_for_binlog | OFF |
-------------------------------------------------------------------------------------------------------
| innodb_log_arch_dir | |
-------------------------------------------------------------------------------------------------------
| innodb_log_archive | OFF |
-------------------------------------------------------------------------------------------------------
| innodb_log_buffer_size | 1048576 |
-------------------------------------------------------------------------------------------------------
| innodb_log_file_size | 5242880 |
-------------------------------------------------------------------------------------------------------
| innodb_log_files_in_group | 2 |
-------------------------------------------------------------------------------------------------------
| innodb_log_group_home_dir | ./ |
-------------------------------------------------------------------------------------------------------
| innodb_max_dirty_pages_pct | 90 |
-------------------------------------------------------------------------------------------------------
| innodb_max_purge_lag | 0 |
-------------------------------------------------------------------------------------------------------
| innodb_mirrored_log_groups | 1 |
-------------------------------------------------------------------------------------------------------
| innodb_open_files | 300 |
-------------------------------------------------------------------------------------------------------
| innodb_rollback_on_timeout | OFF |
-------------------------------------------------------------------------------------------------------
| innodb_support_xa | ON |
-------------------------------------------------------------------------------------------------------
| innodb_sync_spin_loops | 20 |
-------------------------------------------------------------------------------------------------------
| innodb_table_locks | ON |
-------------------------------------------------------------------------------------------------------
| innodb_thread_concurrency | 8 |
-------------------------------------------------------------------------------------------------------
| innodb_thread_sleep_delay | 10000 |
-------------------------------------------------------------------------------------------------------
| interactive_timeout | 28800 |
-------------------------------------------------------------------------------------------------------
| join_buffer_size | 131072 |
-------------------------------------------------------------------------------------------------------
| key_buffer_size | 16777216 |
-------------------------------------------------------------------------------------------------------
| key_cache_age_threshold | 300 |
-------------------------------------------------------------------------------------------------------
| key_cache_block_size | 1024 |
-------------------------------------------------------------------------------------------------------
| key_cache_division_limit | 100 |
-------------------------------------------------------------------------------------------------------
| language | /usr/share/mysql/english/ |
-------------------------------------------------------------------------------------------------------
| large_files_support | ON |
-------------------------------------------------------------------------------------------------------
| large_page_size | 0 |
-------------------------------------------------------------------------------------------------------
| large_pages | OFF |
-------------------------------------------------------------------------------------------------------
| lc_time_names | en_US |
-------------------------------------------------------------------------------------------------------
| license | GPL |
-------------------------------------------------------------------------------------------------------
| local_infile | ON |
-------------------------------------------------------------------------------------------------------
| locked_in_memory | OFF |
-------------------------------------------------------------------------------------------------------
| log | OFF |
-------------------------------------------------------------------------------------------------------
| log_bin | OFF |
-------------------------------------------------------------------------------------------------------
| log_bin_trust_function_creators | OFF |
-------------------------------------------------------------------------------------------------------
| log_error | |
-------------------------------------------------------------------------------------------------------
| log_queries_not_using_indexes | OFF |
-------------------------------------------------------------------------------------------------------
| log_slave_updates | OFF |
-------------------------------------------------------------------------------------------------------
| log_slow_queries | OFF |
-------------------------------------------------------------------------------------------------------
| log_warnings | 1 |
-------------------------------------------------------------------------------------------------------
| long_query_time | 10 |
-------------------------------------------------------------------------------------------------------
| low_priority_updates | OFF |
-------------------------------------------------------------------------------------------------------
| lower_case_file_system | OFF |
-------------------------------------------------------------------------------------------------------
| lower_case_table_names | 0 |
-------------------------------------------------------------------------------------------------------
| max_allowed_packet | 16776192 |
-------------------------------------------------------------------------------------------------------
| max_binlog_cache_size | 18446744073709551615 |
-------------------------------------------------------------------------------------------------------
| max_binlog_size | 104857600 |
-------------------------------------------------------------------------------------------------------
| max_connect_errors | 10 |
-------------------------------------------------------------------------------------------------------
| max_connections | 100 |
-------------------------------------------------------------------------------------------------------
| max_delayed_threads | 20 |
-------------------------------------------------------------------------------------------------------
| max_error_count | 64 |
-------------------------------------------------------------------------------------------------------
| max_heap_table_size | 16777216 |
-------------------------------------------------------------------------------------------------------
| max_insert_delayed_threads | 20 |
-------------------------------------------------------------------------------------------------------
| max_join_size | 18446744073709551615 |
-------------------------------------------------------------------------------------------------------
| max_length_for_sort_data | 1024 |
-------------------------------------------------------------------------------------------------------
| max_prepared_stmt_count | 16382 |
-------------------------------------------------------------------------------------------------------
| max_relay_log_size | 0 |
-------------------------------------------------------------------------------------------------------
| max_seeks_for_key | 18446744073709551615 |
-------------------------------------------------------------------------------------------------------
| max_sort_length | 1024 |
-------------------------------------------------------------------------------------------------------
| max_sp_recursion_depth | 0 |
-------------------------------------------------------------------------------------------------------
| max_tmp_tables | 32 |
-------------------------------------------------------------------------------------------------------
| max_user_connections | 0 |
-------------------------------------------------------------------------------------------------------
| max_write_lock_count | 18446744073709551615 |
-------------------------------------------------------------------------------------------------------
| multi_range_count | 256 |
-------------------------------------------------------------------------------------------------------
| myisam_data_pointer_size | 6 |
-------------------------------------------------------------------------------------------------------
| myisam_max_sort_file_size | 9223372036854775807 |
-------------------------------------------------------------------------------------------------------
| myisam_recover_options | OFF |
-------------------------------------------------------------------------------------------------------
| myisam_repair_threads | 1 |
-------------------------------------------------------------------------------------------------------
| myisam_sort_buffer_size | 8388608 |
-------------------------------------------------------------------------------------------------------
| myisam_stats_method | nulls_unequal |
-------------------------------------------------------------------------------------------------------
| ndb_autoincrement_prefetch_sz | 32 |
-------------------------------------------------------------------------------------------------------
| ndb_force_send | ON |
-------------------------------------------------------------------------------------------------------
| ndb_use_exact_count | ON |
-------------------------------------------------------------------------------------------------------
| ndb_use_transactions | ON |
-------------------------------------------------------------------------------------------------------
| ndb_cache_check_time | 0 |
-------------------------------------------------------------------------------------------------------
| ndb_connectstring | |
-------------------------------------------------------------------------------------------------------
| net_buffer_length | 16384 |
-------------------------------------------------------------------------------------------------------
| net_read_timeout | 600 |
-------------------------------------------------------------------------------------------------------
| net_retry_count | 10 |
-------------------------------------------------------------------------------------------------------
| net_write_timeout | 72000 |
-------------------------------------------------------------------------------------------------------
| new | OFF |
-------------------------------------------------------------------------------------------------------
| old_passwords | OFF |
-------------------------------------------------------------------------------------------------------
| open_files_limit | 1024 |
-------------------------------------------------------------------------------------------------------
| optimizer_prune_level | 1 |
-------------------------------------------------------------------------------------------------------
| optimizer_search_depth | 62 |
-------------------------------------------------------------------------------------------------------
| pid_file | /var/run/mysqld/mysqld.pid |
-------------------------------------------------------------------------------------------------------
| port | 3306 |
-------------------------------------------------------------------------------------------------------
| preload_buffer_size | 32768 |
-------------------------------------------------------------------------------------------------------
| profiling | OFF |
-------------------------------------------------------------------------------------------------------
| profiling_history_size | 15 |
-------------------------------------------------------------------------------------------------------
| protocol_version | 10 |
-------------------------------------------------------------------------------------------------------
| query_alloc_block_size | 8192 |
-------------------------------------------------------------------------------------------------------
| query_cache_limit | 1048576 |
-------------------------------------------------------------------------------------------------------
| query_cache_min_res_unit | 4096 |
-------------------------------------------------------------------------------------------------------
| query_cache_size | 16777216 |
-------------------------------------------------------------------------------------------------------
| query_cache_type | ON |
-------------------------------------------------------------------------------------------------------
| query_cache_wlock_invalidate | OFF |
-------------------------------------------------------------------------------------------------------
| query_prealloc_size | 8192 |
-------------------------------------------------------------------------------------------------------
| range_alloc_block_size | 2048 |
-------------------------------------------------------------------------------------------------------
| read_buffer_size | 131072 |
-------------------------------------------------------------------------------------------------------
| read_only | OFF |
-------------------------------------------------------------------------------------------------------
| read_rnd_buffer_size | 262144 |
-------------------------------------------------------------------------------------------------------
| relay_log_purge | ON |
-------------------------------------------------------------------------------------------------------
| relay_log_space_limit | 0 |
-------------------------------------------------------------------------------------------------------
| rpl_recovery_rank | 0 |
-------------------------------------------------------------------------------------------------------
| secure_auth | OFF |
-------------------------------------------------------------------------------------------------------
| secure_file_priv | |
-------------------------------------------------------------------------------------------------------
| server_id | 0 |
-------------------------------------------------------------------------------------------------------
| skip_external_locking | ON |
-------------------------------------------------------------------------------------------------------
| skip_networking | OFF |
-------------------------------------------------------------------------------------------------------
| skip_show_database | OFF |
-------------------------------------------------------------------------------------------------------
| slave_compressed_protocol | OFF |
-------------------------------------------------------------------------------------------------------
| slave_load_tmpdir | /tmp/ |
-------------------------------------------------------------------------------------------------------
| slave_net_timeout | 3600 |
-------------------------------------------------------------------------------------------------------
| slave_skip_errors | OFF |
-------------------------------------------------------------------------------------------------------
| slave_transaction_retries | 10 |
-------------------------------------------------------------------------------------------------------
| slow_launch_time | 2 |
-------------------------------------------------------------------------------------------------------
| socket | /var/run/mysqld/mysqld.sock |
-------------------------------------------------------------------------------------------------------
| sort_buffer_size | 2097144 |
-------------------------------------------------------------------------------------------------------
| sql_big_selects | ON |
-------------------------------------------------------------------------------------------------------
| sql_mode | |
-------------------------------------------------------------------------------------------------------
| sql_notes | ON |
-------------------------------------------------------------------------------------------------------
| sql_warnings | OFF |
-------------------------------------------------------------------------------------------------------
| ssl_ca | |
-------------------------------------------------------------------------------------------------------
| ssl_capath | |
-------------------------------------------------------------------------------------------------------
| ssl_cert | |
-------------------------------------------------------------------------------------------------------
| ssl_cipher | |
-------------------------------------------------------------------------------------------------------
| ssl_key | |
-------------------------------------------------------------------------------------------------------
| storage_engine | MyISAM |
-------------------------------------------------------------------------------------------------------
| sync_binlog | 0 |
-------------------------------------------------------------------------------------------------------
| sync_frm | ON |
-------------------------------------------------------------------------------------------------------
| system_time_zone | PST |
-------------------------------------------------------------------------------------------------------
| table_cache | 64 |
-------------------------------------------------------------------------------------------------------
| table_lock_wait_timeout | 50 |
-------------------------------------------------------------------------------------------------------
| table_type | MyISAM |
-------------------------------------------------------------------------------------------------------
| thread_cache_size | 8 |
-------------------------------------------------------------------------------------------------------
| thread_stack | 131072 |
-------------------------------------------------------------------------------------------------------
| time_format | %H:%i:%s |
-------------------------------------------------------------------------------------------------------
| time_zone | SYSTEM |
-------------------------------------------------------------------------------------------------------
| timed_mutexes | OFF |
-------------------------------------------------------------------------------------------------------
| tmp_table_size | 33554432 |
-------------------------------------------------------------------------------------------------------
| tmpdir | /tmp |
-------------------------------------------------------------------------------------------------------
| transaction_alloc_block_size | 8192 |
-------------------------------------------------------------------------------------------------------
| transaction_prealloc_size | 4096 |
-------------------------------------------------------------------------------------------------------
| tx_isolation | REPEATABLE-READ |
-------------------------------------------------------------------------------------------------------
| updatable_views_with_limit | YES |
-------------------------------------------------------------------------------------------------------
| version | 5.0.51a-3ubuntu5.8 |
-------------------------------------------------------------------------------------------------------
| version_comment | (Ubuntu) |
-------------------------------------------------------------------------------------------------------
| version_compile_machine | x86_64 |
-------------------------------------------------------------------------------------------------------
| version_compile_os | debian-linux-gnu |
-------------------------------------------------------------------------------------------------------
| wait_timeout | 28800 |
-------------------------------------------------------------------------------------------------------
-
StanislavK
- Devart Team
- Posts: 1710
- Joined: Thu 03 Dec 2009 10:48
I've sent you a test project, please check that it is not blocked by your mail filter. If the sample runs successfully in your environment, please specify what should be changed in it to reproduce the issue, or send us your sample.
As for paging through a result set, you can use the Skip and Take extension methods for this. Please notice that using these methods lead to more complex (and possibly slower) queries.
As for paging through a result set, you can use the Skip and Take extension methods for this. Please notice that using these methods lead to more complex (and possibly slower) queries.
So no matter what I do, I cannot get your sample to break, even mimicking the structures I have. The only thing I can think of is it must be table size related, because as soon as I point your sample at the real database, using my objects, it croaks about 60 rows into the IQueryable Enumerator... I am currently at a loss as to how to proceed.
-
StanislavK
- Devart Team
- Posts: 1710
- Joined: Thu 03 Dec 2009 10:48
Sorry for the delay. Since the problem cannot be reproduced with the table from the sample, but occurs in the actual application, it (the problem) may be connected with a peculiarity of this actual table or the data stored in it. Could you please specify the script of this table and some test data, so that we are able to analyze the situation in more details?
If the table description should not be disclosed, you can, e.g., rename the table/column names to something abstract, like 'table1', 'column1' etc.
If the table description should not be disclosed, you can, e.g., rename the table/column names to something abstract, like 'table1', 'column1' etc.