bash: It's better to have many assoc. arrays with just a few keys instead of one with many keys

x.sh

#!/usr/bin/env bash

AssocTest ()
{
        create1 ()
        {
                declare -g -A Assoc

                declare i
                for ((i=${1?}; i <= ${2?}; i++))
                do
                        Assoc[${i} k1]=$i
                        Assoc[${i} k2]=$i
                done
                #declare -p Assoc
        }

        create2 ()
        {
                declare i

                for ((i=${1?}; i <= ${2?}; i++))
                do
                        declare -g -A "Assoc_${i}=(
                                [k1]='${i}'
                                [k2]='${i}'
                        )"
                        #declare -p "Assoc_${a}"
                done
        }

        retrieve1 ()
        {
                printf 'k1 :=%s\nk2 := %s\n' "${Assoc[${1?} k1]}" "${Assoc[${1} k2]}"
        }

        retrieve2 ()
        {
                declare -n assoc=Assoc_${1?}
                printf 'k1 :=%s\nk2 :=%s\n' "${assoc[k1]}" "${assoc[k2]}"
        }

        {
                time create1 0 "${1?}"
                time create2 0 "$1"
        } >/dev/null


        retrieve ()
        for x in {,,,,}${RANDOM} 111111 {1..1000} -1
        do
                "retrieve${1?}" "$x"
        done >/dev/null

        time retrieve 1
        time retrieve 2
}

TIMEFORMAT=$'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS'

AssocTest 32767
# AssocTest 100
# AssocTest 1000
# AssocTest 10000

# vim: set ts=8 sw=8 tw=0 et :

# GNU bash, version 4.4.0(1)-release (x86_64-pc-linux-gnu)

real    0m2.084s
user    0m2.064s
sys 0m0.016s

real    0m1.857s
user    0m1.812s
sys 0m0.044s

real    0m0.148s
user    0m0.148s
sys 0m0.000s
bash: declare: `Assoc_-1': invalid variable name for name reference

real    0m0.050s
user    0m0.048s
sys 0m0.000s