Postgresql Read from multi-processing

General Usage
2

please show your minimal example …

this code is working for me:

using ProgressMeter, LibPQ, DataFrames, Distributed
addprocs(4)
@everywhere begin
    using ProgressMeter, LibPQ, DataFrames  
    function processSQL(typelike) 
      conn = LibPQ.Connection("dbname=$(ENV["PGDATABASE"]) user=$(ENV["PGUSER"])")       
      result = execute(
          conn,
          "SELECT typname FROM pg_type where typname like '$typelike';";
          throw_error=true,
      )
      df = DataFrame(result)
      close(conn)
      return df
    end
end

sqltypes=["time%","float%","int%"]
nsqltypes=length(sqltypes)
returndf = @showprogress pmap(1:nsqltypes) do i
    processSQL(sqltypes[i])
end

log:

# julia
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.8.0-beta3 (2022-03-29)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

julia> using ProgressMeter, LibPQ, DataFrames, Distributed

julia> addprocs(4)
4-element Vector{Int64}:
 2
 3
 4
 5

julia> @everywhere begin
           using ProgressMeter, LibPQ, DataFrames  
           function processSQL(typelike) 
             conn = LibPQ.Connection("dbname=$(ENV["PGDATABASE"]) user=$(ENV["PGUSER"])")       
             result = execute(
                 conn,
                 "SELECT typname FROM pg_type where typname like '$typelike';";
                 throw_error=true,
             )
             df = DataFrame(result)
             close(conn)
             return df
           end
       end

julia> sqltypes=["time%","float%","int%"]
3-element Vector{String}:
 "time%"
 "float%"
 "int%"

julia> nsqltypes=length(sqltypes)
3

julia> returndf = @showprogress pmap(1:nsqltypes) do i
           processSQL(sqltypes[i])
       end
Progress: 100%|████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| Time: 0:00:12
3-element Vector{DataFrame}:
 5×1 DataFrame
│ Row │ typname     │
│     │ String?     │
├─────┼─────────────┤
│ 1   │ time        │
│ 2   │ time_stamp  │
│ 3   │ timestamp   │
│ 4   │ timestamptz │
│ 5   │ timetz      │
 2×1 DataFrame
│ Row │ typname │
│     │ String? │
├─────┼─────────┤
│ 1   │ float4  │
│ 2   │ float8  │
 10×1 DataFrame
│ Row │ typname        │
│     │ String?        │
├─────┼────────────────┤
│ 1   │ int2           │
│ 2   │ int2vector     │
│ 3   │ int4           │
│ 4   │ int4multirange │
│ 5   │ int4range      │
│ 6   │ int8           │
│ 7   │ int8multirange │
│ 8   │ int8range      │
│ 9   │ internal       │
│ 10  │ interval       │

julia>
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