Changes between Version 17 and Version 18 of IppToPspsDatastorePV3Descriptions

Timestamp:

Nov 5, 2015, 11:35:37 PM (11 years ago)

Author:

chambers

Comment:

--

IppToPspsDatastorePV3Descriptions

@@ -15 +15 @@
 == Step 2 ==
 
-There are 8 DXlayer machines, each dxlayer machine is assigned to 4 contiguous Declination of the layers. These do not have to be Alternatively, the 8 DXlayers are subdivided into 4 layers in declination, making the 32 in total. To aid in the convenience of making batches, the boundaries between these layers will be round to the nearest integer degree Declination. 
-
+There are 8 DXlayer machines, each dxlayer machine is assigned to 4 contiguous Declination layers.  Alternatively can think of this as the 8 DXlayers each being subdivided into 4 Dec Layers making the 32 in total. To aid in the convenience of making batches, the boundaries between these layers will be round to the nearest integer degree Declination. 
+NOTE distinction be DXLayer and Dec Layer. There are 4 DecLayers per DXLayer. (this was not the original source of the DXLayer term, but it works). 
 [[Image(kens3.png, 600px)]]
 
@@ -33 +33 @@
 DS01-1 is most north and starts at RA >= 0. A SLICE is a sequential set of chunks in increasing RA, with a single chunk from each DXLAYER. )
 labels in plots need to be adjusted. We will then Load by SLICE. i.e  the first 8 datastores cover a complete vertical region covering from Dec 90 to -30 8 chunks of batches. 
-The SLICES will eventually be mismatched horizontally because of the density of sources, but that is fine. After a complete SLICE with 8 DXLAYERS has Loaded we will MERGE. So the number of Merges will by definition be either 6, 12 or 24 depending on batch type as per the table below. 
+The SLICES will eventually be mismatched horizontally because of the density of sources, but that is fine. After a complete SLICE with 8 DXLAYERS has Loaded we will MERGE. So the number of Merges will by definition be either 6, 12 or 24 depending on batch type as per the table below. The slices may need to be STAiRCASED in integer degrees to keep the MERGE efficient. The MERGE time will be dominated by the slowest merge of the 32 Dec Layers - hence the reason we will want to staircase it pretty closely. Either that or define the slices as precisely as the Dec Layers, and modify the batch making code.
+