Dependency::$reusable doesn't work resulting in many DB queries

[githubjeka]

<?php
Yii::$app->db->beginCache(
    null, 
    new \yii\caching\DbDependency(['sql' => 'SELECT MAX(updateAt) FROM sector']));
?>
<?= $piping->getLine() ?>
<?= $piping->getLineOnBalance() ?>
<?= $piping->getLineOffBalance() ?>
<?= $piping->getLineBeforeOffBalance() ?>
<?= $piping->getLineAftereOffBalance() ?>

<?php
Yii::$app->db->endCache();
?>

in logs

1   14:53:07.133    0.0 ms  yii\db\Connection::open Opening DB connection: mysql:host=localhost;dbname=inspection_ts
2   14:53:07.133    0.0 ms  yii\db\Command::query   SELECT MAX(updateAt) FROM sector
3   14:53:07.133    0.0 ms  yii\db\Command::query   SELECT MAX(updateAt) FROM sector
4   14:53:07.148    0.0 ms  yii\db\Command::query   SELECT MAX(updateAt) FROM sector
5   14:53:07.148    0.0 ms  yii\db\Command::query   SELECT MAX(updateAt) FROM sector
6   14:53:07.148    0.0 ms  yii\db\Command::query   SELECT MAX(updateAt) FROM sector

Why repeatedly perform dependent sql?

p.s.

 'cache' => ['class' => 'yii\caching\FileCache'],

[samdark]

It's logging regardless getting from db or cache, I think.

[resurtm]

There is dedicated property for customizing that behavior. Check the \yii\caching\Dependency::$reusable property.

[githubjeka]

 public $reusable = false;

[resurtm]

@githubjeka, have you tried to turn it on and check the result? :-)

[githubjeka]

I try ^_^. But there false, obviously the same as it is disabled.

[resurtm]

@githubjeka, yes, and you suggest us to change its default value?

[githubjeka]

does not matter $reusable = true or false. i get five logs yii\db\Command::query SELECT MAX(updateAt) FROM sector

[samdark]

Can you check the following? If it doesn't work it should be a bug.

<?php
Yii::$app->db->beginCache(
    null, 
    new \yii\caching\DbDependency(['sql' => 'SELECT MAX(updateAt) FROM sector', 'reusable' => true]));
?>
<?= $piping->getLine() ?>
<?= $piping->getLineOnBalance() ?>
<?= $piping->getLineOffBalance() ?>
<?= $piping->getLineBeforeOffBalance() ?>
<?= $piping->getLineAftereOffBalance() ?>

<?php
Yii::$app->db->endCache();
?>

[githubjeka]

i tried - not work

[samdark]

Looks like Dependency::getHasChanged() logic is flawed. i.e. serialize result will be different after adding stuff to $_reusableData.

[githubjeka]

In \yii\db\Command::queryInternal

 if (($result = $cache->get($cacheKey)) !== false) {
                Yii::trace('Query result served from cache', 'yii\db\Command::query');
                return $result;
            }

should not be performed repeatedly. Here ($cache->get) it is necessary to stop him. How? :)

[samdark]

@githubjeka it's not query cache level, it's dependency level that should be fixed.

[githubjeka]

$cache->get call $value[1]->getHasChanged($this) and call

  if (!$this->reusable) {
            return $this->generateDependencyData($cache) !== $this->data;

How to stop him on the second sql:

<?= $piping->getLine() ?>
<?= $piping->getLineOnBalance() ?>
<?= $piping->getLineOffBalance() ?>
<?= $piping->getLineBeforeOffBalance() ?>
<?= $piping->getLineAftereOffBalance() ?>

[samdark]

See #3052 (comment)

[samdark]

I've renamed the issue.

[qiangxue]

@githubjeka Could you update and try again? Thanks.

[githubjeka]

Not work:
see my comment #3052 (comment)

$reusable = false; and work the

  if (!$this->reusable) {
            return $this->generateDependencyData($cache) !== $this->data;

PR not fixed this, it essentially has not changed this section.
4674f5b#diff-25b027a479beaf1cc92348af5e3acbafR52

In short, everything is still.

[githubjeka]

But...

I delete folder cache and set $reusable = false; - not work. I get five rows inside logs.

Delete forlder cache and set $reusable = true; , this work, but work like false. I get one row SELECT MAX(updateAt) FROM sector.

It turns out if you want to reusable , then reusable is false. Is this logical?

[githubjeka]

Revised his views, is all logical. Everything works. Thanks.