Should I store country names in MySQL for each user?

Question

Below is a PHP array I have, it has countries list 1 to 228 with name and a number for that country. I used this on an old project where in the MySQL DB I saved a user's country as a number and then I could use this array to avoid doing another MySQL query on pages.

Now I am doing a different site where performance is important. Would it be best to leave it how I am doing it or to change this and store the actual country name into the DB for each user? Which way would most likely be best performance wise?

$country_array = array("1" => "Afghanistan","2" => "Albania","3" => "Algeria","4" => "American Samoa","5" => "Andorra","6" => "Angola","7" => "Anguilla","8" => "Antarctica","9" => "Antigua and Barbuda","10" => "Argentina","11" => "Armenia","12" => "Aruba","13" => "Australia","14" => "Austria","15" => "Azerbaijan","16" => "Bahamas","17" => "Bahrain","18" => "Bangladesh","19" => "Barbados","20" => "Belarus","21" => "Belgium","22" => "Belize","23" => "Benin","24" => "Bermuda","25" => "Bhutan","26" => "Bolivia","27" => "Bosnia and Herzegowina","28" => "Botswana","29" => "Bouvet Island","30" => "Brazil","31" => "British Indian Ocean Territory","32" => "British Virgin Islands","33" => "Brunei Darussalam","34" => "Bulgaria","35" => "Burkina Faso","36" => "Burundi","37" => "Cambodia","38" => "Cameroon","40" => "Cape Verde","41" => "Cayman Islands","42" => "Central African Republic","43" => "Chad","44" => "Chile","45" => "China","46" => "Christmas Island","47" => "Cocos (Keeling) Islands","48" => "Colombia","49" => "Comoros","50" => "Congo","51" => "Cook Islands","52" => "Costa Rica","53" => "Cote D'ivoire","54" => "Croatia","55" => "Cuba","56" => "Cyprus","57" => "Czech Republic","58" => "Czechoslovakia","59" => "Denmark","60" => "Djibouti","61" => "Dominica","62" => "Dominican Republic","63" => "East Timor","64" => "Ecuador","65" => "Egypt","66" => "El Salvador","67" => "Equatorial Guinea","68" => "Eritrea","69" => "Estonia","70" => "Ethiopia","71" => "Falkland Islands (Malvinas)","72" => "Faroe Islands","73" => "Fiji","74" => "Finland","75" => "France","76" => "France, Metropolitan","77" => "French Guiana","78" => "French Polynesia","79" => "French Southern Territories","80" => "Gabon","81" => "Gambia","82" => "Georgia","83" => "Germany","84" => "Ghana","85" => "Gibraltar","86" => "Greece","87" => "Greenland","88" => "Grenada","89" => "Guadeloupe","90" => "Guam","91" => "Guatemala","92" => "Guinea","93" => "Guinea-Bissau","94" => "Guyana","95" => "Haiti","96" => "Heard and McDonald Islands","97" => "Honduras","98" => "Hong Kong","99" => "Hungary","100" => "Iceland","101" => "India","102" => "Indonesia","103" => "Iraq","104" => "Ireland","105" => "Islamic Republic of Iran","106" => "Israel","107" => "Italy","108" => "Jamaica","109" => "Japan","110" => "Jordan","111" => "Kazakhstan","112" => "Kenya","113" => "Kiribati","114" => "Korea","115" => "Korea, Republic of","116" => "Kuwait","117" => "Kyrgyzstan","118" => "Laos","119" => "Latvia","120" => "Lebanon","121" => "Lesotho","122" => "Liberia","123" => "Libyan Arab Jamahiriya","124" => "Liechtenstein","125" => "Lithuania","126" => "Luxembourg","127" => "Macau","128" => "Macedonia","129" => "Madagascar","130" => "Malawi","131" => "Malaysia","132" => "Maldives","133" => "Mali","134" => "Malta","135" => "Marshall Islands","136" => "Martinique","137" => "Mauritania","138" => "Mauritius","139" => "Mayotte","140" => "Mexico","141" => "Micronesia","142" => "Moldova, Republic of","143" => "Monaco","144" => "Mongolia","145" => "Montserrat","146" => "Morocco","147" => "Mozambique","148" => "Myanmar","149" => "Namibia","150" => "Nauru","151" => "Nepal","152" => "Netherlands","153" => "Netherlands Antilles","154" => "New Caledonia","155" => "New Zealand","156" => "Nicaragua","157" => "Niger","158" => "Nigeria","159" => "Niue","160" => "Norfolk Island","161" => "Northern Mariana Islands","162" => "Norway","163" => "Oman","164" => "Pakistan","165" => "Palau","166" => "Panama","167" => "Papua New Guinea","168" => "Paraguay","169" => "Peru","170" => "Philippines","171" => "Pitcairn","172" => "Poland","173" => "Portugal","174" => "Puerto Rico","175" => "Qatar","176" => "Reunion","177" => "Romania","178" => "Russian Federation","179" => "Rwanda","180" => "Saint Lucia","181" => "Samoa","182" => "San Marino","183" => "Sao Tome and Principe","184" => "Saudi Arabia","185" => "Senegal","186" => "Seychelles","187" => "Sierra Leone","188" => "Singapore","189" => "Slovakia","190" => "Slovenia","191" => "Solomon Islands","192" => "Somalia","193" => "South Africa","194" => "Spain","195" => "Sri Lanka","196" => "St. Helena","197" => "St. Kitts And Nevis","198" => "St. Pierre and Miquelon","199" => "St. Vincent And The Greadines","200" => "Sudan","201" => "Suriname","202" => "Svalbard and Jan Mayen Islands","203" => "Swaziland","204" => "Sweden","205" => "Switzerland","206" => "Syrian Arab Republic","207" => "Taiwan","208" => "Tajikistan","209" => "Tanzania, United Republic of","210" => "Thailand","211" => "Togo","212" => "Tokelau","213" => "Tonga","214" => "Trinidad and Tobago","215" => "Tunisia","216" => "Turkey","217" => "Turkmenistan","218" => "Turks and Caicos Islands","219" => "Tuvalu","220" => "Uganda","221" => "Ukraine","222" => "United Arab Emirates","225" => "United States Virgin Islands","226" => "Uruguay","227" => "Uzbekistan","228" => "Vanuatu","229" => "Vatican City State","230" => "Venezuela","231" => "Viet Nam","232" => "Wallis And Futuna Islands","233" => "Western Sahara","234" => "Yemen","235" => "Yugoslavia","236" => "Zaire","237" => "Zambia","238" => "Zimbabwe");

Answer 1

It would be fastest to keep a table called countries and a field on your users table called country or country_id that holds the foreign key for each users country in the countries table.

A join in MYSQL is normally (almost always) faster than iterating through a list of returned records and pairing the country with the user.

Answer 2

Edit: on second pass, consider all of what I said below about strings, but opt for an enum field. Create an enum in the database containing all countries, and use that rather than strings or another table. It should give you all of the benefits of using strings (like getting the value you want back without a join) and all of the benefits of using a second table.

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Assuming that your primary use case is something to the effect of "get me all users and country" or "get me user N and country" then the fastest you can do is to store the string.

This has some pitfalls: string compares are more costly than say an indexed approach (discussed in another answer), and if you plan on often running something to the effect of "get me all users from country X" where you know the index well then you can avoid the string compare.

Even if the latter case exists, it really only pays to have another table if the latter case dominates the usage, the data is going to be changing (you plan on adding new countries later, updating the names of the countries), if you want to change the language of the name of the country to change based on some user locale, etc.

Avoiding joins will save you some execution time, but a second table could also be right for you.