MySQL 在一个非常简单的查询上非常慢

Question

I'm getting very slow response running a very simple query in a small table (115k records)... It takes about 8sec to respond, and I can't figure out why it's taking that long. Any advice would be awesome

Table:

CREATE TABLE `financeiro_fluxo` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `branch` int(10) unsigned NOT NULL,
  `abertura` int(10) DEFAULT NULL,
  `origem` int(10) unsigned DEFAULT NULL,
  `status_pagamento` tinyint(3) unsigned DEFAULT NULL,
  `conta` int(10) unsigned NOT NULL,
  `tipo_lancamento` tinyint(3) unsigned NOT NULL,
  `categoria` int(10) unsigned NOT NULL,
  `tipo_entidade` varchar(32) COLLATE utf8_unicode_ci NOT NULL,
  `entidade` int(10) unsigned DEFAULT NULL,
  `entidade_input` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
  `tipo_pagamento` tinyint(3) unsigned NOT NULL,
  `parcela` smallint(5) unsigned NOT NULL,
  `parcelas` smallint(5) unsigned NOT NULL,
  `valor` decimal(12,2) NOT NULL,
  `valor_taxa` decimal(12,2) DEFAULT NULL,
  `valor_troco` decimal(12,2) DEFAULT NULL,
  `confirmado` tinyint(3) unsigned DEFAULT NULL,
  `data_confirmacao` datetime DEFAULT NULL,
  `vencimento` date NOT NULL,
  `info` varchar(510) COLLATE utf8_unicode_ci DEFAULT NULL,
  `bandeira` int(10) unsigned DEFAULT NULL,
  `user_add` int(10) unsigned NOT NULL,
  `user_last` int(10) unsigned NOT NULL,
  `param_ref` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
  `param` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
  `file` int(10) unsigned DEFAULT NULL,
  `date_created` datetime NOT NULL,
  `date_modified` datetime NOT NULL,
  `status` smallint(6) unsigned NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=116749 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci

Query:

SELECT * from financeiro_fluxo

Explain:

id  select_type     table               type    key   key_len   rows   
1   SIMPLE          financeiro_fluxo    ALL                     116244  

The same query running on localhost with the same table, returns in less than a sec...

Profile:

Answer 1

Seems you are doing a full table scan because your query does not include any limiting conditions (for example WHERE clause or LIMIT). To let the query preform better use indexed columns with some kind of criteria. What happens if you add WHERE id IS NOT NULL

I assume you need all the records, if not limit the result set by added conditions in a more specific WHERE clause (on a indexed column) or a LIMIT clause.

Answer 2

Will the "reports" aggregate data? Of so, you could speed up the 8 second (remote) query by doing more work in the server, thereby shipping less data across the wire.

That is, think about whether AVG(..), COUNT(*), SUM(..), MAX(..) , etc can be done in the SELECT .

Taking that another step... Build and maintain a "Summary table" that has subtotals (etc). Then, reading (or scanning) the summary table and summing up the subtotals, etc, will be even faster, both in the Server and across the wire.

(And I agree with the need to avoid * , and that the 8 seconds is probably due to.network delay (and "bandwidth"). Where is the server geographically? How long does SELECT 1; take?)