TL; DR
A consulta que o Visual Studio está executando está sendo bloqueada e a consulta atinge o tempo limite.
Acontece que eu consegui resolver isso para a nossa situação: tempo limite devido ao bloqueio!
Executei um rastreamento de criador de perfil com um filtro no nome do aplicativo do Microsoft SQL Server Data Tools, Comparação de esquemas para capturar os eventos de comparação de esquema do Visual Studio.
Atingiria uma determinada consulta e depois pararia, quando o VS alegaria que a comparação estava concluída.
Aqui está o lote de consultas em questão:
select object_id as id,
null as id2,
case
when [type] != 'D ' then [type]
when parent_object_id != 0 then 'D '
else 'LD'
end as [type],
schema_name(schema_id) as name1,
name as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.objects
where
type != 'S'
and is_ms_shipped != 1
union
select principal_id as id,
null as id2,
type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.database_principals
union
select assembly_id as id,
null as id2,
'CLR' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
null as v1,
modify_date as mod
from sys.assemblies
where
is_user_defined =1
union
select schema_id as id,
null as id2,
'SCH' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
null as v1,
null as mod
from sys.schemas
union
select user_type_id as id,
null as id2,
case
when is_assembly_type = 1 then 'UDT'
when is_table_type = 1 then 'TT'
else 'UDDT'
end as [type],
schema_name(schema_id) as name1,
name as name2,
null as name3,
null as a1,
binary_checksum(system_type_id, schema_id, max_length, precision, scale, is_nullable, is_assembly_type, default_object_id, rule_object_id) as v1,
null as mod
from sys.types
where
is_user_defined = 1
union
select idx.object_id as id,
idx.index_id as id2,
case
when idx.type = 3 then 'XIX'
when idx.type = 4 then 'SIX'
when idx.type = 6 then 'CIX'
else 'IDX'
end as [type],
schema_name(tab.schema_id) as name,
tab.name as name2,
idx.name as name3,
null as a1,
binary_checksum(is_unique, data_space_id, ignore_dup_key, is_primary_key, is_unique_constraint, fill_factor, is_padded, is_disabled, allow_row_locks, allow_page_locks) as v1,
null as mod
from sys.indexes idx
inner join sys.tables tab on idx.object_id = tab.object_id
where
idx.is_primary_key = 0
and idx.name is not null
and idx.is_unique_constraint = 0
and idx.is_hypothetical = 0
union
select stat.object_id as id,
stat.stats_id as id2,
'STAT' as [type],
schema_name(tab.schema_id) as name,
tab.name as name2,
stat.name as name3,
null as a1,
no_recompute as v1,
null as mod
from sys.stats stat
inner join sys.tables tab on stat.object_id = tab.object_id
where
stat.user_created = 1
union
select xml_collection_id as id,
null as id2,
'XSC' as type,
schema_name(schema_id),
name as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.xml_schema_collections
where xml_collection_id > 1
union
select
object_id id,
null id2,
'DDT' as type,
name,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.triggers
where
parent_class = 0
union
select
database_specification_id id,
null as id2,
'DAS' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.database_audit_specifications
union
select
certificate_id id,
null as id2,
'CERT' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
binary_checksum(pvt_key_encryption_type, thumbprint) as v1,
null as mod
from sys.certificates
union
select
asymmetric_key_id id,
null as id2,
'ASMK' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
null as v1,
null as mod
from sys.asymmetric_keys
union
select
symmetric_key_id id,
null as id2,
case
when name = N'##MS_DatabaseMasterKey##' then 'MK'
else 'SYMK'
end as type,
case
when name = N'##MS_DatabaseMasterKey##' then null
else name
end as name1,
null as name2,
null as name3,
principal_id as a1,
null as v1,
modify_date as mod
from sys.symmetric_keys
where
name = N'##MS_DatabaseMasterKey##'
or name not like N'##%'
union
select
fulltext_catalog_id id,
null as id2,
'FTC' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
binary_checksum(is_default, is_accent_sensitivity_on) as v1,
null as mod
from sys.fulltext_catalogs
union
select
ft.object_id id,
ft.unique_index_id as id2,
'FTI' as type,
schema_name(o.schema_id) as name1,
o.name as name2,
null as name3,
null as a1,
binary_checksum(is_enabled, change_tracking_state) as v1,
null as mod
from sys.fulltext_indexes ft
inner join sys.objects o on ft.object_id = o.object_id
union
select
stoplist_id id,
null as id2,
'FTSL' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
null as v1,
modify_date as mod
from sys.fulltext_stoplists
union
select
data_space_id id,
null as id2,
[type] as type,
name as name1,
null as name2,
null as name3,
null as a1,
is_default as v1,
null as mod
from sys.data_spaces
union
select
function_id id,
null as id2,
'PF' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.partition_functions
union
select
file_id id,
null as id2,
'FILE' as type,
name as name1,
null as name2,
null as name3,
null as a1,
binary_checksum(type, data_space_id, physical_name, state, growth, is_read_only, is_sparse, is_percent_growth) as v1,
null as mod
from sys.database_files
union
select
message_type_id id,
null as id2,
'MT' as [type],
name collate database_default as name1,
null as name2,
null as name3,
principal_id as a1,
binary_checksum(validation, xml_collection_id) as v1,
null as mod
from sys.service_message_types
union
select
service_contract_id id,
null as id2,
'SC' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
null as v1,
null as mod
from sys.service_contracts
union
select
service_id id,
null as id2,
'SERVICE' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
binary_checksum(service_queue_id) as v1,
null as mod
from sys.services
union
select
route_id id,
null as id2,
'ROUTE' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
binary_checksum(remote_service_name, broker_instance, lifetime, address, mirror_address) as v1,
null as mod
from sys.routes
union
select
remote_service_binding_id id,
null as id2,
'RSB' as type,
name as name1,
null as name2,
null as name3,
principal_id as a1,
binary_checksum(service_contract_id, remote_principal_id, is_anonymous_on) as v1,
null as mod
from sys.remote_service_bindings
union
select
object_id id,
null as id2,
'DEN' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.event_notifications
union
select
priority_id id,
null as id2,
'SBP' as type,
name as name1,
null as name2,
null as name3,
null as a1,
binary_checksum(service_contract_id, local_service_id, remote_service_name, priority) as v1,
null as mod
from sys.conversation_priorities
union
select
principal_id id,
null as id2,
'LOG' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.server_principals
where
type != 'R'
union
select
audit_id id,
null as id2,
'SAD' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.server_audits
union
select
credential_id id,
null as id2,
'CRD' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.credentials
union
select
msg.message_id id,
msg.language_id as id2,
'SEM' as type,
cast(msg.message_id as sysname) as name1,
lang.alias collate database_default as name2,
null as name3,
null as a1,
binary_checksum(msg.severity, msg.is_event_logged, msg.text) as v1,
null as mod
from sys.messages msg inner join sys.syslanguages lang on (msg.language_id = lang.lcid)
where
msg.message_id > 50000
union
select
base.endpoint_id id,
null as id2,
'SEP' as type,
base.name as name1,
null as name2,
null as name3,
base.principal_id as a1,
binary_checksum(*) as v1,
null as mod
from sys.endpoints base
left outer join sys.http_endpoints http on (base.endpoint_id = http.endpoint_id)
left outer join sys.service_broker_endpoints sb on (base.endpoint_id = sb.endpoint_id)
left outer join sys.soap_endpoints soap on (base.endpoint_id = soap.endpoint_id)
left outer join sys.tcp_endpoints tcp on (base.endpoint_id = tcp.endpoint_id)
left outer join sys.database_mirroring_endpoints mirror on (base.endpoint_id = mirror.endpoint_id)
union
select
server_id id,
null as id2,
'SLS' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.servers
union
select
logins.server_id id,
logins.local_principal_id as id2,
'SLL' as type,
srvs.name as name1,
lp.name as name2,
null as name3,
null as a1,
null as v1,
logins.modify_date as mod
from sys.linked_logins logins
inner join sys.servers srvs on (logins.server_id = srvs.server_id)
left join sys.server_principals lp on (logins.local_principal_id = lp.principal_id)
union
select
object_id id,
null as id2,
'SST' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.server_triggers
where
is_ms_shipped = 0
union
select
server_specification_id id,
null as id2,
'SAS' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
modify_date as mod
from sys.server_audit_specifications
union
select
event_session_id id,
null as id2,
'SES' as type,
name as name1,
null as name2,
null as name3,
null as a1,
null as v1,
null as mod
from sys.server_event_sessions
union
select
provider_id id,
null as id2,
'SCP' as type,
name as name1,
null as name2,
null as name3,
null as a1,
binary_checksum(guid, version, dll_path, is_enabled) as v1,
null as mod
from sys.cryptographic_providers
select
cast(32 as tinyint) as class,
'SES' as type,
event_session_id as majorid,
binary_checksum(event_id, name, package, module) as minorid,
name as name,
null as id1,
null as id2
from sys.server_event_session_actions
union
select
cast(32 as tinyint) as class,
'SES' as type,
event_session_id as majorid,
event_id as minorid,
name as name,
binary_checksum(predicate) as id1,
null as id2
from sys.server_event_session_events
union
select
cast(32 as tinyint) as class,
'SES' as type,
event_session_id as majorid,
object_id as minorid,
name as name,
binary_checksum(value) as id1,
null as id2
from sys.server_event_session_fields
union
select
cast(32 as tinyint) as class,
'SES' as type,
event_session_id as majorid,
event_id as minorid,
name as name,
null as id1,
null as id2
from sys.server_event_session_events
union
select
perms.class as class,
objectpropertyex(perms.major_id, 'BaseType') as type,
perms.major_id as majorid,
perms.minor_id as minorid,
perms.type + perms.state collate database_default as name,
perms.grantee_principal_id as id1,
perms.grantor_principal_id as id2
from sys.database_permissions perms
where
perms.major_id >= 0
union
select
props.class as class,
case
when objs.parent_object_id > 0 then objectpropertyex(objs.parent_object_id, 'BaseType')
else objectpropertyex(props.major_id, 'BaseType')
end as type,
case
when objs.parent_object_id > 0 then objs.parent_object_id
else props.major_id
end as majorid,
props.minor_id as minorid,
props.name as name,
binary_checksum(props.value) as id1,
null as id2
from sys.extended_properties props left outer join sys.objects objs on props.major_id = objs.object_id
union
select
cast(4 as tinyint) as class,
'R' as type,
roles.role_principal_id as majorid,
roles.member_principal_id as minorid,
'drm' as name,
null as id1,
null as id2
from sys.database_role_members roles
union
select
cast(6 as tinyint) as class,
'TT' as type,
tt.user_type_id as majorid,
cols.column_id as minorid,
cols.name as name,
binary_checksum(cols.user_type_id, cols.max_length, cols.precision, cols.scale,
cols.collation_name, cols.is_nullable, cols.is_ansi_padded, cols.is_rowguidcol, cols.is_identity,
cols.is_computed, cols.is_xml_document, cols.xml_collection_id, cols.default_object_id, cols.rule_object_id) as id1,
null as id2
from sys.table_types tt inner join sys.columns cols on (tt.type_table_object_id = cols.object_id)
select
cols.object_id as tableid,
cols.column_id as columnid,
binary_checksum(cols.name) as checksum
from sys.tables tabs
inner join sys.columns cols on (tabs.object_id = cols.object_id)
inner join sys.index_columns idx_cols on (idx_cols.object_id = tabs.object_id and idx_cols.column_id = cols.column_id)
where
tabs.is_ms_shipped = 0
union
select
object_id as tableid,
column_id as columnid,
binary_checksum(type_column_id, language_id) as checksum
from sys.fulltext_index_columns
A execução da consulta no SSMS nunca terminaria a execução no servidor incorreto, mas levaria menos de um segundo em todos os outros ambientes.
Então comecei a separá-lo e descobri que as consultas que estavam lendo das três visualizações do sistema a seguir eram o problema:
sys.server_event_session_actionssys.server_event_session_eventssys.server_event_session_fields
A primeira dessas exibições de sistema continha apenas 28 registros (encontrados ao executar a Count(*)), mas não retornaria os dados a menos que eu usasse a (NOLOCK)dica ... [b] problema de bloqueio !
Descobrir a cabeça da cadeia de bloqueio foi fácil, mas não era passível de matança, pois era uma sessão de Eventos Estendidos. Há uma correção para esse problema aqui: https://support.microsoft.com/en-gb/kb/2511963
Mas espero que, no seu caso, você possa simplesmente matar a cabeça da corrente e retornar as coisas ao normal!
EDIT: Tendo agora uma janela de manutenção viável para o SQL Server afetado, uma reinicialização limpou o SPID e agora as comparações estão funcionando mais uma vez!
Além disso, aqui está um script rápido que escrevi para encontrar o chefe da (s) cadeia (s) de bloqueio que pode ser útil para futuros leitores: http://gvee.co.uk/files/sql/admin.blocking_chains.sql
IF Object_ID('admin.blocking_chains', 'V') IS NULL
BEGIN
EXEC ('CREATE VIEW admin.blocking_chains AS SELECT NULL As buffer;');
END
;
GO
ALTER VIEW admin.blocking_chains
AS
WITH processes AS (
SELECT s.spid
, s.blocked As blocking_spid
, DB_Name(s.dbid) As database_name
, s.program_name
, Cast(x.text As varchar(Max)) As definition
, hostname As host_name
, loginame As login_name
, nt_domain
, nt_username
FROM sys.sysprocesses (NOLOCK) As s
CROSS
APPLY sys.dm_exec_sql_text(s.sql_handle) As x
WHERE s.spid > 50
)
, blocking (spid, blocking_spid, blocking_statement, sequence, level, database_name) AS (
SELECT s.spid
, s.blocking_spid
, s.definition
, Row_Number() OVER (ORDER BY s.spid) As sequence
, 0 As level
, s.database_name
FROM processes As s
INNER
JOIN processes As s1
ON s1.blocking_spid = s.spid
WHERE s.blocking_spid = 0
UNION ALL
SELECT r.spid
, r.blocking_spid
, r.definition
, d.sequence
, d.level + 1
, r.database_name
FROM processes As r
INNER
JOIN blocking As d
ON d.spid = r.blocking_spid
WHERE r.blocking_spid > 0
)
, results AS (
SELECT blocking_spid
, spid
, blocking_statement
, level
, Min(sequence) As sequence
, Min(database_name) As database_name
FROM blocking
GROUP
BY blocking_spid
, spid
, blocking_statement
, level
)
SELECT Cast(CASE WHEN results.blocking_spid = 0 THEN 1 ELSE 0 END As bit) As is_head_of_chain
, results.sequence
, results.level
, results.database_name
, results.spid
, results.blocking_spid
, results.blocking_statement
, processes.host_name
, processes.program_name
, processes.login_name
, processes.nt_domain
, processes.nt_username
, Right('0000' + Cast(results.sequence As varchar(11)), 5) + '-' + Right('0000' + Cast(results.level As varchar(11)), 5) As sort_order
FROM results
LEFT
JOIN processes
ON processes.spid = results.spid
;