I found that in previous version of patch I missed PageSetLSN and PageSetTLI, but huge amount of WAL is still here. Also I found that huge amount of WAL appears only with -O2. With -O0 amount of WAL is ok, but messages "FATAL: xlog flush request BFF11148/809A600 is not satisfied --- flushed only to 44/9C518750" appears. Seems that there is some totally wrong use of WAL if even optimization level does matter...
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With best regards,
Alexander Korotkov.