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"Best" approaches don't generally exist, but storing only geometry in one database, and everything else in another, then linking between them in real time is an anti-pattern that approaches worst case. The least-worst case solution set has all the data for each table in one place. There are many ways to get there, but they all require more details than is really appropriate for a public forum (and often involve multi-month implementation contracts). I have implemented change detection solutions that use a hash of the data row contents to identify which records have changed over time, so that only the records which need update are updated, allowing me to keep table collections exceeding 160 million rows in sync with 20 minutes of processing for 200k-800k (often redundant) change messages a day (ironically, the system generating the change messages takes 4-5 hours to identify the change candidates, and most of those 20 minutes are due to transmission delay across a wide area network). Suffice it to say that "maintenance" and "publication" databases are in your near future. If you calculate a reasonably secure hash during data ingest into a staging table, and preserve the hash of the existing data as you load it, you can drive a simple UPDATE statement into the publishing tables in nearly no time, without any publishing downtime. - V
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yesterday
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I just went through something like this with an architecture dataset I was toying with, though it was hundredths of feet, not sub-millimeter rounding. The default coordinate reference generally preserves thousandths of meters, though some dip into the ten-thousandths. Unfortunately, it varies by coordinate system (max resolution across the entire mappable space). The only way to change ArcGIS coordinate reference behavior is to take proactive ownership of the coordinate reference used in your data conversion. The first step here is to read (and understand) the Understanding Coordinate Management in the Geodatabase White Paper. Then you need to determine your actual XY/Z/M coordinate reference range requirements and determine the exact offsets and scales necessary to accomplish them. At that point, you can create a Feature Dataset which uses these values. And then all data conversion should go though that Feature Dataset. Since spatial references are immutable, once the feature class is created inside the FDS, you can drag it back out to the parent file/enterprise geodatabase. You should also consider whether tenth-millimeter precision is actually necessary. I can assure you that the carpenter building my retirement home is not going to achieve better than 1/16" precision, possibly as little as 1/4". - V
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a week ago
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As a SQL query, it's pretty basic but doing this in Python is a bit trickier, since you have to do the inner query in memory. The key is to chunk the features into rows by Y, so you can order by X. Then you need to flip the listed X values on alternate rows. I'm on a deadline, so I can't offer even a rough untested code block. - V
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3 weeks ago
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Relying on feature order based on OID is kindof iffy. The only way to change OID is to create a new feature class in the order you desire, so this isn't an UpdateCursor task, but an InsertCursor one. Getting the "back-and-forth" numbering is a matter of assigning bands (by Y value), then using modulus-2 of band-number to assign left-to-right or right-to-left order. - V
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3 weeks ago
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File group configuration is controlled by the "storage keyword" environment (using an "ON filegroup" in the storage clause). I always create my tables with SQL then register them, so then the file group allocation is trivial. Of course, you can use SQL Server tools to migrate storage via a clustered index as well. In the days of petabyte disk arrays, file group management is mostly a waste of time for tiny things like vector data under a quarter-billion rows. - V
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3 weeks ago
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Measurements in Web Mercator aren't really in meters. The poles are infinitely far from the Equator, so distance accuracy is wrong to start (sphere), and gets worse as latitude magnitude increases (at roughly tan(latitude)). Never measure ANYTHING in Web Mercator, because it can't give a correct answer. If you're working in MD State Plane, keep on using MD State Plane to get accurate distances. - V
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a month ago
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There's a bunch of information missing here: What version of ArcGIS are you using? What product? What is the coordinate system used in the display canvas? What is the coordinate system of the Buffer source? What is the coordinate system of the Buffer output? Where is the data located? What exact parameters did you provide to the Buffer command? What is the actual measured distance? There are many potential causes, but the most common is use of a coordinate system for which distance is undefined, like Web Mercator. - V
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a month ago
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Please provide an example of the invalid polygon coordinates.
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07-16-2024
07:30 AM
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While latitude has hard limits on values ([-90,90]), longitude does not. pi radians is equivalent in every way to 3pi radians and 2pi, 0, and -2pi are equivalent as well. There may be limitations in storage of coordinate values in SQL Server, which, like Esri's ST_Geometry, uses integer internal representation, but values between -360 degrees and +360 degrees ought to be safe. STDistance(), if done correctly for geodesic values, should not find any distance at all between 278.440065912902 and -81.559934087098 with the same latitude. Measuring in Cartesian degrees is of course useless for all purposes. So it seems your problem is not with the longitude values but with distance measurement. You would need to edit or reply to your own post with a more specific description of that issue to get a useful answer. - V
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07-04-2024
11:15 AM
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From my About page: Note: Please do not try to message me directly or tag me in questions; just ask a question in an appropriate community, and if I see it, have something to add, and have the time, I'll respond. Tagging me in questions is more likely to reduce the time I have to answer, and delay whatever response I might have. - V
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06-28-2024
08:38 AM
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Note that you should never store user data in the SDE schema, so the "from sde.fc" part is a problem. Best practice is to create a new login to own spatial data (and a new tablespace to store the data for that login). Using the SDE login for this is akin to using SYSTEM or DBO for noodling, or web surfing the dark net as administrator -- It's not likely to end well. - V
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06-14-2024
07:35 AM
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There's a whole lot of unclear things here, which is probably why there hasn't been a response. So, please answer the following questions: What version (and service pack level) of ArcMap are you using? What exact version of QGIS are you using? What exact version of PostgreSQL are you using? What exact privileges are bestowing using GRANT wizard ? How is one of the affected tables defined (the complete CREATE TABLE as reported by pgAdmin)? What version of pgAdmin are you using? At what exact version is your geodatabase? What "solutions" have you tried that didn't work? You can either reply below or edit the original question to contain this information. - V
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06-13-2024
02:26 PM
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Four vertices is a triangle, not a square. A square would have five vertices. Edit: I should add that this is pretty much worst practice (aka "antipattern"). Using five vertices to store a pixel could only be made worse by using 9 or 21. On the extremely rare occasions where converting a raster to vector made sense in my own data models, it was only as a point, and only briefly. I'd suggest your colleague review why this is necessary before moving deeper into the process. - V
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06-07-2024
12:07 PM
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Uh, oh. That's Null Island (wrong coordinate system issue). Have you tried using Check Geometry and/or Repair Geometry on the source layer(s)? - V
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05-31-2024
07:27 AM
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IMHO, copy/paste of each feature class is the road to ruin, because all versions need to be deleted and the entire instance compressed first, or all data in An/Dn tables will be lost. If you move the data in the database using database tools, you move the versioning as well (the backup needs to span the geodatabase tables -- sde.sde/gdb_* and all the schemas which own tables managed in the geodatabase), and you don't need to have a versioning fire sale (Crazy Vince says all data must go!). The single biggest issue here is that you can't change the name of the database after restore (that messes up the registry). If the table schemas have changed in dev, you need a much more detailed migration plan. - V
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05-30-2024
10:54 AM
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