# \#juliadb

**URL:** https://discourse.julialang.org/tag/juliadb/245.md

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

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## [Very Slow \`DBInterface.execute\` on large duckdb relative to R](https://discourse.julialang.org/t/very-slow-dbinterface-execute-on-large-duckdb-relative-to-r/121984)

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**Author:** [@floswald](https://discourse.julialang.org/u/floswald)\
**Replies:** 4\
**Last updated:** [October 30, 2024, 9:11pm UTC](https://discourse.julialang.org/t/very-slow-dbinterface-execute-on-large-duckdb-relative-to-r/121984 "2024-10-30T21:11:59Z")

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Hi all, I’ve made a clone of @grantmcdermott 's nice workshop on duckdb and polars - adding a chapter on julia and duckdb. He had pointed out some very slow julia timings in his slides, and actually created an issue on …

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## [Grouped Data Frames](https://discourse.julialang.org/t/grouped-data-frames/94116)

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**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 8\
**Last updated:** [February 7, 2023, 8:59am UTC](https://discourse.julialang.org/t/grouped-data-frames/94116 "2023-02-07T08:59:01Z")

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I find querying a JuliaDB IndexedTable is 20% faster than a DataFrame. But selecting a group from a GroupedDataFrame (GDF) is 200 times faster. So I’d like to work more with GDFs. I notice New columns in the und…

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## [Moving to juliadb from dataframes and getting error joining tables, dataframes join ok](https://discourse.julialang.org/t/moving-to-juliadb-from-dataframes-and-getting-error-joining-tables-dataframes-join-ok/83894)

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**Author:** [@bww00](https://discourse.julialang.org/u/bww00)\
**Replies:** 1\
**Last updated:** [July 8, 2022, 7:21pm UTC](https://discourse.julialang.org/t/moving-to-juliadb-from-dataframes-and-getting-error-joining-tables-dataframes-join-ok/83894 "2022-07-08T19:21:54Z")

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Moving to juliadb from dataframes and getting error joining 2 tables. ERROR: LoadError: UndefRefError: access to undefined reference error is on the join statement tables load ok. Any help appreciated code and error…

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## [Cannot Install JuliaDB](https://discourse.julialang.org/t/cannot-install-juliadb/53057)

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**Author:** [@PikaPhD](https://discourse.julialang.org/u/PikaPhD)\
**Replies:** 2\
**Last updated:** [October 28, 2021, 1:34pm UTC](https://discourse.julialang.org/t/cannot-install-juliadb/53057 "2021-10-28T13:34:07Z")

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I am trying to install JuliaDB so I can start learning how to use databases in Juila. I am having a conflict with StatsBase. If I understand the error message correctly, JuliaDB requires version 0.13.1 or earlier of Sta…

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## [Sql Server connection string in ODBC.jl](https://discourse.julialang.org/t/sql-server-connection-string-in-odbc-jl/50367)

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**Author:** [@Cristian\_Suciava](https://discourse.julialang.org/u/Cristian_Suciava)\
**Replies:** 2\
**Last updated:** [July 16, 2021, 4:45am UTC](https://discourse.julialang.org/t/sql-server-connection-string-in-odbc-jl/50367 "2021-07-16T04:45:39Z")

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I use this code to connect to a Sql Server database, with no credentials All good! ODBC.adddsn("SQL\_Server\_DSN", "SQL Server"; SERVER="x", DATABASE ="x", Trusted\_Connection="True") conn = DBInterface.connect(ODBC…

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## [JuliaDB groupby many columns](https://discourse.julialang.org/t/juliadb-groupby-many-columns/58935)

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**Author:** [@Fabien1](https://discourse.julialang.org/u/Fabien1)\
**Replies:** 0\
**Last updated:** [April 9, 2021, 5:10pm UTC](https://discourse.julialang.org/t/juliadb-groupby-many-columns/58935 "2021-04-09T17:10:20Z")

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Hi guys , I’m trying to groupby using JuliaDB , everything works well except when i want to apply a function that takes two columns in one time. JuliaDB.groupby( ( TOTAL\_PAID = :PRICE =\> sum, FREQ…

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## [Percentage change method in JuliaDB](https://discourse.julialang.org/t/percentage-change-method-in-juliadb/58883)

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**Author:** [@quantiota](https://discourse.julialang.org/u/quantiota)\
**Replies:** 0\
**Last updated:** [April 8, 2021, 10:07pm UTC](https://discourse.julialang.org/t/percentage-change-method-in-juliadb/58883 "2021-04-08T22:07:45Z")

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Hey, is there any percentchange method that calculates the percentage change only between timestamps in a JuliaDB column.

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## [Cannot convert String to series data for plotting](https://discourse.julialang.org/t/cannot-convert-string-to-series-data-for-plotting/58763)

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**Author:** [@quantiota](https://discourse.julialang.org/u/quantiota)\
**Replies:** 0\
**Last updated:** [April 7, 2021, 3:12pm UTC](https://discourse.julialang.org/t/cannot-convert-string-to-series-data-for-plotting/58763 "2021-04-07T15:12:38Z")

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hey trying to work with JuliaDB by example from just added a first column for the curency market. month = 1 window = Dates.Hour(1) # 1) subset data (lazy) date\_range = DateTime(2019, 1):Dates.Millisecond(1):DateTime…

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## [Can't install juliadb](https://discourse.julialang.org/t/cant-install-juliadb/56633)

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**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 2\
**Last updated:** [March 6, 2021, 10:11pm UTC](https://discourse.julialang.org/t/cant-install-juliadb/56633 "2021-03-06T22:11:28Z")

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I’m not sure what my options are here. Thoughts/recommendations? (@v1.5) pkg\> add JuliaDB Resolving package versions… ERROR: Unsatisfiable requirements detected for package Plots \[91a5bcdd\]: Plots \[91a5bcdd\] log: ├…

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## [Larger than memory table format with lazy reads?](https://discourse.julialang.org/t/larger-than-memory-table-format-with-lazy-reads/45123)

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**Author:** [@sairus7](https://discourse.julialang.org/u/sairus7)\
**Replies:** 5\
**Last updated:** [August 19, 2020, 12:33pm UTC](https://discourse.julialang.org/t/larger-than-memory-table-format-with-lazy-reads/45123 "2020-08-19T12:33:09Z")

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Let’s say, I have some storage with a table-like data in it. For example, it is a single big binary file with serialized array of StoredRow structures: struct StoredRow a::Float64 b::Float64 c::UInt16 end A…

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## [Changing values and type of JuliaDB column](https://discourse.julialang.org/t/changing-values-and-type-of-juliadb-column/43921)

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**Author:** [@john\_b](https://discourse.julialang.org/u/john_b)\
**Replies:** 0\
**Last updated:** [July 29, 2020, 8:46pm UTC](https://discourse.julialang.org/t/changing-values-and-type-of-juliadb-column/43921 "2020-07-29T20:46:06Z")

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As a newcomer to Julia and JuliaDB, I have a simple question. Given a JuliaDB table, how would I map a function to a column that changes the column values and type? For example: import JuliaDB import Dates function col…

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## [Can't launch jupyter from Juliabox](https://discourse.julialang.org/t/cant-launch-jupyter-from-juliabox/40199)

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**Author:** [@aebk2015](https://discourse.julialang.org/u/aebk2015)\
**Replies:** 2\
**Last updated:** [May 26, 2020, 6:52pm UTC](https://discourse.julialang.org/t/cant-launch-jupyter-from-juliabox/40199 "2020-05-26T18:52:52Z")

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I am unable to launch jupyter from Juliabox. I just registered; can log in from Juliabox but then I am presented with the launch page which is not activated: see below, thanks

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## [Package Installation Failing May 2020 - DataFrames ,CSV](https://discourse.julialang.org/t/package-installation-failing-may-2020-dataframes-csv/39352)

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**Author:** [@eyedia](https://discourse.julialang.org/u/eyedia)\
**Replies:** 6\
**Last updated:** [May 13, 2020, 6:43pm UTC](https://discourse.julialang.org/t/package-installation-failing-may-2020-dataframes-csv/39352 "2020-05-13T18:43:21Z")

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Today (5/12/2020, 5th May 2020 getting this on Julia TLS (1.0.5) version. It’s our production environment. Help please!! Code: using Pkg Pkg.add(Pkg.PackageSpec(;name=“LearnBase”, version=“0.3”)) specific version was…

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## [Unique rows in distributed table](https://discourse.julialang.org/t/unique-rows-in-distributed-table/36549)

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**Author:** [@Jakob](https://discourse.julialang.org/u/Jakob)\
**Replies:** 1\
**Last updated:** [March 27, 2020, 7:14pm UTC](https://discourse.julialang.org/t/unique-rows-in-distributed-table/36549 "2020-03-27T19:14:13Z")

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Hi, how do I get the unique rows of a Distributed Table in JuliaDB? df = table(\["a", "a", "a", "b", "b"\], \["x", "x", "y", "x", "x"\], names = (:X1, :X2), chunks = 2) julia\> df Distributed Table with 5 rows in 2 chunks:…

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## [Error when performing join on Distributed Tables (JuliaDB)](https://discourse.julialang.org/t/error-when-performing-join-on-distributed-tables-juliadb/35800)

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**Author:** [@Jakob](https://discourse.julialang.org/u/Jakob)\
**Replies:** 0\
**Last updated:** [March 10, 2020, 2:40pm UTC](https://discourse.julialang.org/t/error-when-performing-join-on-distributed-tables-juliadb/35800 "2020-03-10T14:40:53Z")

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Hi, I get the error message shown below when trying to do the following out-of-core join: t209\_expanded = join(t209, t201\_sel, broadcast = :right, how = :left, lkey = :appln\_id, rkey = :appln\_id) Both input tables are…

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## [Using JuliaDB for online applications (time-series circular storage)](https://discourse.julialang.org/t/using-juliadb-for-online-applications-time-series-circular-storage/34610)

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**Author:** [@caxelrud](https://discourse.julialang.org/u/caxelrud)\
**Replies:** 0\
**Last updated:** [February 14, 2020, 1:12am UTC](https://discourse.julialang.org/t/using-juliadb-for-online-applications-time-series-circular-storage/34610 "2020-02-14T01:12:29Z")

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I am designing an application that stores time-series data (several fields with a time-stamp). It will require frequent periodic inserts for recent data (or appends) and infrequent deletes (for the oldest data). The ide…

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## [JuliaDB parsing unix epoch field](https://discourse.julialang.org/t/juliadb-parsing-unix-epoch-field/33805)

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**Author:** [@toms](https://discourse.julialang.org/u/toms)\
**Replies:** 0\
**Last updated:** [January 26, 2020, 10:07am UTC](https://discourse.julialang.org/t/juliadb-parsing-unix-epoch-field/33805 "2020-01-26T10:07:36Z")

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Hello Julia community, I’m trying to loadndsparse a csv file with a unix epoch field and turn it into a Julia DateTime . What would be the correct way to do this in Julia? I’ve tried using the colparsers option but am…

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## [Empty JuliaDB](https://discourse.julialang.org/t/empty-juliadb/33450)

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**Author:** [@alphasig329](https://discourse.julialang.org/u/alphasig329)\
**Replies:** 1\
**Last updated:** [January 16, 2020, 10:57pm UTC](https://discourse.julialang.org/t/empty-juliadb/33450 "2020-01-16T22:57:19Z")

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Is it possible to initialize an empty JuliaDB table with columns names?

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## [How to change the type of a variable for a loaded table?](https://discourse.julialang.org/t/how-to-change-the-type-of-a-variable-for-a-loaded-table/32973)

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**Author:** [@kai](https://discourse.julialang.org/u/kai)\
**Replies:** 11\
**Last updated:** [January 6, 2020, 9:34pm UTC](https://discourse.julialang.org/t/how-to-change-the-type-of-a-variable-for-a-loaded-table/32973 "2020-01-06T21:34:36Z")

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I’m trying to use JuliaDB to load tables and then use MixedModels to fit models. The MixedModels package requires the clustering variable “id” to be categorical, but in my dataset “id” is integer. So my question is, ho…

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## [Working with U.S. Census Bureau Microdata](https://discourse.julialang.org/t/working-with-u-s-census-bureau-microdata/31014)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 10\
**Last updated:** [November 14, 2019, 1:13am UTC](https://discourse.julialang.org/t/working-with-u-s-census-bureau-microdata/31014 "2019-11-14T01:13:33Z")

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Hello, I’m just plugging a recent video I did on how to work with the American Community Survey public-use microdata files from the U.S. Census Bureau. I show how to download the data from the Census, save to tables to …

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## [First part benchmarking medium-data tools](https://discourse.julialang.org/t/first-part-benchmarking-medium-data-tools/28260)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 4\
**Last updated:** [September 1, 2019, 9:41pm UTC](https://discourse.julialang.org/t/first-part-benchmarking-medium-data-tools/28260 "2019-09-01T21:41:51Z")

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I compared and contrast JuliaDB with Dask and disk.frame. http://diskframe.com/articles/vs-dask-juliadb.html Probably more to come, but JuliaDB needs to mature before it can be a contender in these benchmarks.

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## [Most efficient way to compute number of rows in each group using JuliaDB?](https://discourse.julialang.org/t/most-efficient-way-to-compute-number-of-rows-in-each-group-using-juliadb/28256)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 0\
**Last updated:** [September 1, 2019, 8:01am UTC](https://discourse.julialang.org/t/most-efficient-way-to-compute-number-of-rows-in-each-group-using-juliadb/28256 "2019-09-01T08:01:37Z")

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Suppose a is a JuliaDB table, is the below the best (most efficient) way to compute the number of rows per group? using LambdaFn, DataFrames, JuliaDB a = DataFrame(Column1 = rand(\["a", "b", "c"\], 1\_000), b = rand(1000))…

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## [Trying to analyse Fannie Mae data with JuliaDB](https://discourse.julialang.org/t/trying-to-analyse-fannie-mae-data-with-juliadb/21410)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 14\
**Last updated:** [August 31, 2019, 11:27pm UTC](https://discourse.julialang.org/t/trying-to-analyse-fannie-mae-data-with-juliadb/21410 "2019-08-31T23:27:45Z")

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I am doing my best to analyse Fannie Mae data with JuliaDB. However the f First Step is to download the Fannie Mae Data and unzip them all Now I tried to load the data using loadtable but it didn’t work. So I split th…

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## [Accumulating distributed data](https://discourse.julialang.org/t/accumulating-distributed-data/28117)

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**Author:** [@grahamas](https://discourse.julialang.org/u/grahamas)\
**Replies:** 0\
**Last updated:** [August 28, 2019, 3:56pm UTC](https://discourse.julialang.org/t/accumulating-distributed-data/28117 "2019-08-28T15:56:52Z")

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I’m running distributed simulations and hoping to save the results as I go – the aggregate results are too big to hold in memory. Can someone point me to a good way to do this that doesn’t amount to saving each run in a…

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## [JuliaDB saving arrays](https://discourse.julialang.org/t/juliadb-saving-arrays/28059)

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**Author:** [@grahamas](https://discourse.julialang.org/u/grahamas)\
**Replies:** 1\
**Last updated:** [August 27, 2019, 7:35pm UTC](https://discourse.julialang.org/t/juliadb-saving-arrays/28059 "2019-08-27T19:35:37Z")

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I’m running a parameter sweep solving differential equations and trying to save the results, and have a couple questions: When I try to save a toy example as follows, I get an error that \_impl is not defined for my arg…

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## [Julia and Python optimization programmer with machine learning experience](https://discourse.julialang.org/t/julia-and-python-optimization-programmer-with-machine-learning-experience/27602)

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**Author:** [@GdMacmillan](https://discourse.julialang.org/u/GdMacmillan)\
**Replies:** 5\
**Last updated:** [August 18, 2019, 9:15am UTC](https://discourse.julialang.org/t/julia-and-python-optimization-programmer-with-machine-learning-experience/27602 "2019-08-18T09:15:57Z")

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Built production Python library used to convert electromagnetic data from physical sensors to real valued power flow models. Worked with technical directory to turn scripts written in Scilab to a data science toolkit in …

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## [IndexedTable to DataFrame](https://discourse.julialang.org/t/indexedtable-to-dataframe/26528)

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**Author:** [@bernhard](https://discourse.julialang.org/u/bernhard)\
**Replies:** 3\
**Last updated:** [August 5, 2019, 8:17am UTC](https://discourse.julialang.org/t/indexedtable-to-dataframe/26528 "2019-08-05T08:17:32Z")

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I am wondering how to convert an IndexedTable to a DataFrame. There are two posts that offer (partial) solutions to this, but I am not sure if that is (still) the best way. For now, it is not clear to me when it is pr…

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## [Question: JuliaDB and regression models](https://discourse.julialang.org/t/question-juliadb-and-regression-models/17723)

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**Author:** [@Juan](https://discourse.julialang.org/u/Juan)\
**Replies:** 16\
**Last updated:** [July 16, 2019, 10:43am UTC](https://discourse.julialang.org/t/question-juliadb-and-regression-models/17723 "2019-07-16T10:43:50Z")

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How do you use JuliaDB for tasks such as fitting a regression model with random effects? (like MixedEffects.jl but with datasets larger than memory)

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## [JuliaDB loading data](https://discourse.julialang.org/t/juliadb-loading-data/26281)

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**Author:** [@bernhard](https://discourse.julialang.org/u/bernhard)\
**Replies:** 15\
**Last updated:** [July 12, 2019, 6:03pm UTC](https://discourse.julialang.org/t/juliadb-loading-data/26281 "2019-07-12T18:03:03Z")

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I am trying out Julia DB, but am unable to read data. Any ideas what is going wrong here? loadndsparse is running into an error (the error also happens when I sue Float64 for all types). using JuliaDB using CSV #using…

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## [JuliaDBMeta/JuliaDB - How to select columns dynamically/programatically](https://discourse.julialang.org/t/juliadbmeta-juliadb-how-to-select-columns-dynamically-programatically/26082)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 3\
**Last updated:** [July 9, 2019, 11:19am UTC](https://discourse.julialang.org/t/juliadbmeta-juliadb-how-to-select-columns-dynamically-programatically/26082 "2019-07-09T11:19:52Z")

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I’ve been beating my head against the wall for hours on end trying to figure out how to avoid hard-coding column names in the below example (specifically, in the array comprehension wgts = \[sum(cols(Symbol("PWGTP$i"))) f…

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