主库或备库存在断开的复制槽 解决方法之一 9.6引入了old_snapshot_threshold参数,表示快照超过多长时间后,vacuum就可以删除其保留的dead tuple。单位是分钟,默认为-1,表示禁止该特性。这样可以避免表膨胀,但是长事务读取被删除tuple时会报错,snapshot too old 参考资料 Postgresql的表膨胀及对策 ...
虽然设置参数old_snapshot_threshold可以解决垃圾无法回收问题,那只对于持有xmin的快照事务,而持有xid的事务这个参数是不生效的。 开启快照过旧,对性能有影响。 因为每次获取快照都要更新SNAPSHOT TOO OLD需要用到的数据结构列表。同时get buffer page时,每次都要判断,是否满足快照过旧。
(Nilsson et al., 2002). Such a threshold seems too high and not characteristic of old-growth systems at global level; it would exclude several old-growth stands in our dataset. Indeed about 90% of the old-growth stands in our dataset contained more than 30 LLT per ha, therefore, we ...
your snapshot testing just found a difference from the origin document to current received one - a single space character was added to the markdown... ✏ Code Examples ⚪ ️1.9 Avoid global test fixtures and seeds, add data per-test ✅ Do: Going by the golden rule (bullet 0),...
- set SET "_highthreshold_undoretention"=max(maxquerylen)+1 2. Long running queries which can raise tuned_undoretention to very high values. 2. 长时间运行的查询可能会将 tuned_undoretention 提升到非常高的值 You need to tune these queries to avoid retain UNDO data for more time inside UNDO...
- new: x265 switches --dup-threshold, --frame-dup - new: nvenc switches --multiref-l0, --multiref-l1 - new: StaxRip can use MediaInfo.NET instead of the built-in MediaInfo GUI, it requires MediaInfo.NET to be installed and started at least once - fix: FFTW not always asked to be...
It'll probably monitor what portion of the memory is still free as it does this, and perhaps when available memory gets under some threshold, start opening a lot more files, but only requesting the first portion and perhaps the last portion (ID3 tag) to be cached. When these requests ...
From Ch. de la Tour, the Clos de Vougeots had much to admire, but also enough hints of VA to cause me to reserve judgment until after bottling (VA is a complex subject—small amounts can give lift and vibrancy to a wine, and the threshold of acceptability can vary greatly among even...
Hi dear users, I need your feedback for the next version of Flowcharting : [0.9.1b SNAPSHOT] - 2020-11-08 Added New initialization engine for drawio libs New notifier handler in panel. Change default url draw.io by https://embed.diagrams...
what are the default threshold values for Average disk bytes/write and Average disk bytes/read What are these links to windows-ppe.net? What causes a workstation to lose trust with the domain controller? What disk is \Device\Harddisk6\DR6 What does "Standby" mean is "Resource Monitor" ?