Query the Data Delivery Network
Query the DDNThe easiest way to query any data on Splitgraph is via the "Data Delivery Network" (DDN). The DDN is a single endpoint that speaks the PostgreSQL wire protocol. Any Splitgraph user can connect to it at data.splitgraph.com:5432 and query any version of over 40,000 datasets that are hosted or proxied by Splitgraph.
For example, you can query the collin_cad_appraisal_data table in this repository, by referencing it like:
"texas-gov/collin-cad-appraisal-data-nne4-8riu:latest"."collin_cad_appraisal_data"or in a full query, like:
SELECT
":id", -- Socrata column ID
"propyear", -- Property Appraisal Year
"propid", -- Property ID (short account number aka Key ID)
"geoid", -- Geographical ID (long account number)
"proptype", -- Property Type (BPP, Manufactured Home, Mineral, Real)
"propsubtype", -- Property Sub Type (BPP, Commercial, Land, Residential)
"propcategorycode", -- PTAD Category Code (see code-file list)
"propusecode", -- Property Use Code
"mapid", -- Map ID
"nbhdcode", -- Neighborhood Code
"marketareacode", -- Market Area Code
"legalabssubcode", -- Abstract/Condo/Subdivision/Mobile Home Park Code
"legalabssubname", -- Abstract/Condo/Subdivision/Mobile Home Park Name
"legalabssubblock", -- Block/Building
"legalabssublot", -- Tract/Lot/Space/Unit
"legaldescription", -- Legal Description
"dbaname", -- "Doing Business As" Name
"compropflag", -- Commercial Property Flag (T/F)
"udipropflag", -- Undivided Interest Property Flag (T/F)
"udigroupid", -- Undivided Interest Group ID
"udiinterestpct", -- Undivided Interest Ownership Percentage
"commoninterestpct", -- Common Elements Interest Percentage
"ecogroupid", -- Economic Group ID
"ecogroupgba", -- Economic Group Gross Building Area
"ecogroupnra", -- Economic Group Net Rentable Area
"propsplitfrompid", -- Property Split-From Property ID
"propcreatedate", -- Property Create Date
"entitycodes", -- All Entity Codes (concatenated; see code-file list)
"entityschoolcode", -- School Entity Code (see code-file list)
"entitycitycode", -- City Entity Code (see code file-list)
"entitymud", -- MUD Entity Flag (T/F)
"entitytif", -- Tax Increment Fund/Reinvestment Zone Flag (T/F)
"entitysbcl", -- Split -By County Line Flag (T/F)
"situsbldgnum", -- Situs Building Number
"situsstreetprefix", -- Situs Street Prefix
"situsstreetname", -- Situs Street Name
"situsstreetsuffix", -- Situs Street Suffix
"situsunit", -- Situs Unit
"situscity", -- Situs City Name
"situszip", -- Situs Zip-Code
"situsconcat", -- Situs Address (concatenated, full)
"situsconcatshort", -- Situs Address (concatenated, no city state zip)
"ownerid", -- Property Owner ID
"ownername", -- Owner Name (primary/line 1)
"ownernameaddtl", -- Owner Name (additional/line 2)
"owneraddrline1", -- Owner Mailing Address Line 1
"owneraddrline2", -- Owner Mailing Address Line 2
"owneraddrcity", -- Owner Mailing Address City
"owneraddrstate", -- Owner Mailing Address State
"owneraddrzip", -- Owner Mailing Address Zip-Code (5+4)
"owneraddrcountry", -- Owner Mailing Address Country Code
"taxagentid", -- Tax Agency ID
"taxagentname", -- Tax Agency Name
"deedtypecd", -- Last Deed Type Code (see code-file list)
"deednum", -- Last Deed County Clerk Instrument Number
"deedbook", -- Last Deed County Clerk Book Number
"deedpage", -- Last Deed County Clerk Page Number
"deedeffdate", -- Last Deed Effective Date
"deedfiledate", -- Last Deed County Clerk File Date
"imprvyearbuilt", -- Main Improvement Year Built
"imprvclasscd", -- Main Improvement Class Code
"imprvmainarea", -- Total Improvement Main Area (aka living area)
"imprvunits", -- Total Improvement Number of Units (if available)
"imprvpoolflag", -- Pool Exists Flag (T/F)
"imprvcategorycodes", -- Improvement PTAD Category Codes (concatenated; see code-file list)
"landtypecode", -- Predominant Land Type Code (see code-file list)
"landsizeacres", -- Total Land Size Acres
"landsizesqft", -- Total Land Size Square Feet
"landagacres", -- Total Land Agricultural Appraisal Acres
"landcategorycodes", -- Land PTAD Category Codes (concatenated; see code-file list)
"exemptcodes", -- Exemption Codes (concatenated; excluding age-related exemptions)
"exempthmstdflag", -- Homestead Exemption Flag (T/F)
"protestcode", -- ARB Protest Indicator (A=Active, C=Closed, H=Heard by ARB)
"propstatus", -- Property Status (InProgress, Preliminary, Certified)
"currvalyear", -- Current Year
"currvalimprv", -- Current Year Improvement Value
"currvalland", -- Current Year Land Value
"currvalmarket", -- Current Year Market Value
"currvalagloss", -- Current Year Ag Loss
"currvalappraised", -- Current Year Appraised Value
"currvalhscaploss", -- Current Year Homestead Cap Loss
"currvalnhscaploss", -- Current Year Non-Homestead Cap Loss
"currvalassessed", -- Current Year Assessed Value
"prevvalyear", -- Previous Year
"prevvalimprv", -- Previous Year Improvement Value
"prevvalland", -- Previous Year Land Value
"prevvalmarket", -- Previous Year Market Value
"prevvalagloss", -- Previous Year Ag Loss
"prevvalappraised", -- Previous Year Appraised Value
"prevvalhscaploss", -- Previous Year Homestead Cap Loss
"prevvalnhscaploss", -- Previous Year Non-Homestead Cap Loss
"prevvalassessed", -- Previous Year Assessed Value
"noticeyear", -- Notice Year
"noticevalimprv", -- Notice Year Improvement Value
"noticevalland", -- Notice Year Land Value
"noticevalmarket", -- Notice Year Market Value
"noticevalagloss", -- Notice Year Ag Loss
"noticevalappraised", -- Notice Year Appraised Value
"noticevalhscaploss", -- Notice Year Homestead Cap Loss
"noticevalnhscaploss", -- Notice Year Non-Homestead Cap Loss
"noticevalassessed", -- Notice Year Assessed Value
"noticedate", -- Notice Date
"datadate" -- Data As-Of Date
FROM
"texas-gov/collin-cad-appraisal-data-nne4-8riu:latest"."collin_cad_appraisal_data"
LIMIT 100;Connecting to the DDN is easy. All you need is an existing SQL client that can connect to Postgres. As long as you have a SQL client ready, you'll be able to query texas-gov/collin-cad-appraisal-data-nne4-8riu with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.texas.gov. When you querytexas-gov/collin-cad-appraisal-data-nne4-8riu:latest on the DDN, we "mount" the repository using the socrata mount handler. The mount handler proxies your SQL query to the upstream data source, translating it from SQL to the relevant language (in this case SoQL).
We also cache query responses on the DDN, but we run the DDN on multiple nodes so a CACHE_HIT is only guaranteed for subsequent queries that land on the same node.
Query Your Local Engine
bash -c "$(curl -sL https://github.com/splitgraph/splitgraph/releases/latest/download/install.sh)"Read the installation docs.
Splitgraph Cloud is built around Splitgraph Core (GitHub), which includes a local Splitgraph Engine packaged as a Docker image. Splitgraph Cloud is basically a scaled-up version of that local Engine. When you query the Data Delivery Network or the REST API, we mount the relevant datasets in an Engine on our servers and execute your query on it.
It's possible to run this engine locally. You'll need a Mac, Windows or Linux system to install sgr, and a Docker installation to run the engine. You don't need to know how to actually use Docker; sgrcan manage the image, container and volume for you.
There are a few ways to ingest data into the local engine.
For external repositories (like this repository), the Splitgraph Engine can "mount" upstream data sources by using sgr mount. This feature is built around Postgres Foreign Data Wrappers (FDW). You can write custom "mount handlers" for any upstream data source. For an example, we blogged about making a custom mount handler for HackerNews stories.
For hosted datasets, where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.
Mounting Data
This repository is an external repository. It's not hosted by Splitgraph. It is hosted by data.texas.gov, and Splitgraph indexes it. This means it is not an actual Splitgraph image, so you cannot use sgr clone to get the data. Instead, you can use the socrata adapter with the sgr mount command. Then, if you want, you can import the data and turn it into a Splitgraph image that others can clone.
First, install Splitgraph if you haven't already.
Mount the table with sgr mount
sgr mount socrata \
"texas-gov/collin-cad-appraisal-data-nne4-8riu" \
--handler-options '{
"domain": "data.texas.gov",
"tables": {
"collin_cad_appraisal_data": "nne4-8riu"
}
}'That's it! Now you can query the data in the mounted table like any other Postgres table.
Query the data with your existing tools
Once you've loaded the data into your local Splitgraph engine, you can query it with any of your existing tools. As far as they're concerned, texas-gov/collin-cad-appraisal-data-nne4-8riu is just another Postgres schema.