mysql - 如何提高嵌套集模型中数千个插入的速度？

Question

我正在使用 MySQL。我想插入 100.000 个属于不同级别(root_id、lft、rgt、level)的嵌套集模型的位置。如果我不必担心树，我会进行批量插入；但在这种情况下，我必须为此订单上的每个对象执行 3 次查询:

foreach ( $places as $place )
{
    # get parent place from $ancestor_array ( woeid => ids )
    $parent = $ancestors[:parent_woeid]

    update place set lft = lft + 2 where root_id = :root_id and lft >= :obj_lft;
    update place set rgt = rgt + 2 where root_id = :root_id and rgt >= :obj_lft;
    insert into place (..., root_id, lft, rgt, level, ...) values (..., :obj_root_id, :obj_lft, :obj_rgt, :obj_level, ...);

    ...
}

这需要很长时间......所以是时候尝试变得更聪明了。这就是我的想法:

foreach ( $places as $place )
{
    # get parent place from $ancestor_array ( woeid => ids )
    $parent = $ancestors[:parent_woeid]

    $new_admins[] = array('parent_woeid' => :parent_woeid, ...data place....)
    $woeids[] = :parent_woeid;
}

# lock + bulk insert of $new_admins with lft=rgt=level=root_id= null + unlock
    insert into place (...) values (...), (...), (...), ...., (...)

# get ids of those places
select from place where woeid in(:array_woeids)

# lock + bulk update with 3 updates per place + unlock
    update place set lft= lft + 2 where root_id = :root_id and lft >= :obj_lft;
    update place set rgt = rgt + 2 where root_id = :root_id and rgt >= :obj_lft;
    update place set lft=:obj_lft, rgt=:obj_rgt where id=:id

# i have to update the ancestors lft & rgt values on the $ancestors_array, 
# because we have them "cached" in the array in order to avoid doing a
# select per inserted place.

你觉得怎么样？你会怎么做？您是否会将所有插入和更新保存到文件中并使用 LOAD DATA INFILE 语法而不是此选项？

我还缺少其他选项吗？

非常感谢!

Answer 1

仅插入项目并仅在插入所有项目时重新计算所有 lft/rgt 索引不是更高效吗？

但是要做到这一点，您必须知道每个项目的父 ID，以便您有索引的基础。我个人成功地为每个数据项保留了 lft + lrg + ParentId，这使得维护变得更加容易(您可以随时进行简单的重新计算/完整性检查)。